All tools

Add a solid border of any width and colour around an image.

Add captions to an image with an outline that stays readable over anything.

Brighten or darken a photo without other editing.

Increase or reduce the difference between light and dark tones.

Make colours more vivid or more muted, up to full greyscale.

Convert AVIF images to JPG in your browser, with no upload and no watermark.

Convert AVIF images to PNG in your browser, with no upload and no watermark.

Replace one colour in an image with another, or make it transparent, with adjustable tolerance.

Apply a Gaussian blur to a whole image, at any radius.

Convert BMP images to JPG in your browser, with no upload and no watermark.

Convert BMP images to PNG in your browser, with no upload and no watermark.

Compress many images at once with a shared quality setting, and see what each saved.

Convert many images to JPG, PNG or WebP at once and download them as a ZIP.

Resize many images to one width at once, keeping proportions, and download a ZIP.

Convert CMYK percentages to RGB and hex for screen use.

Find the closest CSS colour name to any colour, and see whether it is an exact match.

Pick a colour and read it back as hex, RGB, HSL, HSV, CMYK and the nearest CSS name.

See how an image or a pair of colours looks with each type of colour vision deficiency.

Pull the dominant colours out of a picture as HEX, RGB and HSL, with CSS variables.

Build a colour palette from one base colour using harmonies, with contrast ratios and CSS variables.

Turn a colour photo into greyscale, with control over how far to go.

Draw freehand on a blank canvas or over an image, with colours, brush sizes and undo.

See the camera, exposure, date and location data hidden inside a photo.

Convert GIF images to JPG in your browser, with no upload and no watermark.

Convert GIF images to PNG in your browser, with no upload and no watermark.

Convert a hex colour to HSL, plus RGB, HSV and CMYK.

Convert HSL values to RGB and hex, with HSV and CMYK alongside.

Convert ICO images to JPG in your browser, with no upload and no watermark.

Convert ICO images to PNG in your browser, with no upload and no watermark.

Arrange up to 30 images into a grid, with adjustable gaps and background.

Pick colours from an image by clicking, with an adjustable sample area and hex, RGB and HSL values.

Reduce image file size with an adjustable quality setting and a side-by-side before and after comparison.

Convert images between JPG, PNG and WebP, with quality control for the lossy formats.

Crop an image by dragging a selection, with optional fixed aspect ratios such as 1:1 and 16:9.

Identify an image's real format from its bytes, with dimensions and print quality.

See an image's tonal distribution per channel, and how much detail is clipped.

Place one image over another with position, size, opacity and blend mode, then export a PNG.

Resize an image to exact pixel dimensions or a percentage, with the aspect ratio locked by default.

Turn an image into a data URL for inlining, or decode a data URL back into an image.

Resize a photo to Instagram's post, portrait, landscape, story or reel sizes.

Invert an image's colours to produce a photographic negative.

Convert JPG images to PNG in your browser, with no upload and no watermark.

Convert JPG images to WEBP in your browser, with no upload and no watermark.

Resize a photo to common passport and ID photo dimensions at print resolution.

Convert PNG images to JPG in your browser, with no upload and no watermark.

Convert PNG images to WEBP in your browser, with no upload and no watermark.

Make a square profile picture at the size each platform expects.

Strip EXIF, GPS and camera data from a photo, then verify the result is clean.

Convert RGB to CMYK percentages, with hex, HSL and HSV alongside.

Convert RGB values to HSL, plus hex, HSV and CMYK, with a live swatch.

Convert RGB to HSV/HSB, the model behind most colour pickers.

Rotate an image in 90° steps and flip it horizontally or vertically.

Round an image's corners, with the removed areas genuinely transparent.

Frame a screenshot on a gradient background with padding, rounded corners and a drop shadow.

Give a photo a warm, aged sepia tone.

Sharpen, blur, emboss or detect edges with a convolution filter, previewed live.

Resize images for Facebook, X, LinkedIn, Pinterest, TikTok and WhatsApp.

Add emoji stickers to an image by clicking, at a size proportionate to the picture.

Rasterise SVG markup or a file to PNG, JPG or WebP at any scale.

Darken the edges of an image to draw the eye towards the centre.

Convert WEBP images to JPG in your browser, with no upload and no watermark.

Convert WEBP images to PNG in your browser, with no upload and no watermark.

Resize an image to YouTube's thumbnail, banner or profile picture sizes.

Add a header, footer or page numbers to every page of a PDF as real selectable text.

Place a PNG or JPEG onto chosen pages of a PDF, sized as a share of the page width.

Stamp page numbers onto a PDF, with position, format and starting number under your control.

Place text on chosen pages of a PDF, with a font, size, colour and position that repeat across pages.

Draw a diagonal text watermark across a PDF, with colour, size, angle and opacity control.

Shrink a scanned or image-heavy PDF by rendering its pages at a lower resolution.

Trim margins from every page of a PDF by setting the crop box, with an honest note on what that does.

Turn a CSV into a paginated PDF table with sized columns and a header repeated on every page.

Remove pages from a PDF by number or range and download the trimmed document.

Combine images into a single PDF, with page size, orientation and margin control.

Turn JSON into a paginated PDF, re-indented and set in a monospace font.

Turn Markdown into a laid-out PDF with headings, lists, quotes, code blocks and rules.

Find and save the files embedded inside a PDF, decompressing them as it goes.

Draw freehand on a PDF page with a pen, and save the marked-up file.

List the fonts a PDF uses and save the ones embedded inside it.

Fill in a PDF's form fields — text, checkboxes, radio groups and dropdowns — and optionally flatten them.

Drag over a rendered page to highlight it, in any colour, and save the marked-up PDF.

Pull the embedded images out of a PDF and save each one as a PNG.

Pull every link out of a PDF, separating real clickable links from URLs written as text.

Combine several PDFs into one file, in the order you choose, without uploading anything.

Clear the author, title and dates from a PDF's document properties, with an honest note on what stays.

Inspect a PDF's title, author, producer, dates, page count, page size and encryption state.

Rotate every page or just the ones you name, in 90° steps, and keep the change permanently.

See a PDF's encryption state and permission flags, and what those flags actually enforce.

Draw a signature and place it on a page of a PDF, trimmed to the ink and with a transparent background.

Extract a page range into a new PDF, or split a document into one file per page.

Recover tables from a PDF's text positions and export them as CSV.

Pull the text out of a PDF, page by page, ready to copy or download as a text file.

Turn PDF pages into JPG, PNG or WebP images at a resolution you choose.

Inspect a PDF's structure: pages, sizes, rotation, embedded fonts, text layers and metadata.

Rearrange, reverse or remove PDF pages with thumbnails to see what you are moving.

Change every page to A4, Letter or another standard size, scaling content to fit.

Turn an SVG drawing into a PDF, fitted to a page or sized to the artwork.

Turn plain text into a PDF with your choice of page size, font and margins.

Pull the soundtrack out of a video and save it as a WAV file.

Crop an animated GIF to a region, applied across every frame.

Split an animated GIF into its frames and save each as a PNG.

Play an animated GIF backwards, or forwards and then backwards.

Make an animated GIF smaller by reducing its colours or dropping frames.

Resize an animated GIF, keeping every frame and its timing.

Rotate or flip an animated GIF, applied to every frame.

Speed up or slow down an animated GIF, by delays or by dropping frames.

Capture stills from a video as JPG, PNG or WebP, evenly spaced or as a single thumbnail.

Check a video's duration, resolution, aspect ratio and average bitrate.

Turn a few seconds of video into an animated GIF, with control over speed and size.

Convert audio between formats in your browser — MP3 or WAV out, with bitrate, sample rate and channel controls.

Add a fade in, a fade out or both, with a choice of curve that actually matters.

Join several audio files into one, with a gap or a crossfade between them.

Strip ID3 and other metadata from an audio file without re-encoding the audio.

Read the ID3 tags stored in an MP3 — title, artist, album and more.

Measure peak and average levels, then scale the file to a target peak.

Find and remove silent sections from a recording, with a threshold you control.

Play audio faster or slower, with the pitch shifting the way a record does.

Cut a section out of an audio file by dragging the range across a waveform.

Translate a cron expression into plain English, field by field.

Build a cron expression from common schedules and confirm what it will do.

Escape a string so it is valid as a CSS identifier in a selector.

Format CSS with one declaration per line, or minify it for production.

Turn a curl command into JavaScript fetch, Axios or Python requests code.

Find files that are byte-for-byte identical by comparing their SHA-256 hashes.

Pull every email address out of a block of text, deduplicated if you want.

Read raw email headers: delivery path, timings, and SPF, DKIM and DMARC results.

Tidy a list of email addresses: deduplicate, normalise case and find malformed entries.

Turn a .env file into a .env.example, TypeScript types or shell exports, and check it for the usual mistakes.

Produce a list of chosen files with sizes and dates as text, CSV, Markdown or JSON.

Plan a batch rename with find and replace, numbering and case rules, then take the script or the renamed copies.

Convert between bytes, KB, MB, GB and TB in both binary and decimal, with transfer times.

Make filenames safe across operating systems, and see exactly what was wrong with them.

Find the git command for what you are trying to do, with what it does and what it can destroy.

Break a git remote URL into host, owner and repository, and convert between SSH, HTTPS and web forms.

Build a .gitignore from language, framework, editor and operating system sections, with duplicates removed.

Compress or decompress a file with gzip or deflate, using the browser's own compression.

View any file as a hex dump with its text column, and search for bytes or text.

Escape text for safe use in HTML, or decode entities back into readable characters.

Indent messy or minified HTML so it can be read, or strip it back down to one line.

Escape text for a JavaScript string literal, including the </script> case.

Compare two JSON documents structurally, ignoring key order and formatting.

Escape text so it can be embedded safely inside a JSON string.

Format, validate and minify JSON with clear error messages that point at the exact position.

List every key path in a JSON document with its type and how often it appears.

Test a JSONPath-style query against a document and see what it matches.

Infer a draft 2020-12 JSON Schema from a sample document, with format and enum detection.

Check a JSON document against a schema and get a JSON Pointer to every value that fails.

Sort JSON object keys alphabetically at every level, leaving arrays alone.

Turn an escaped JSON string back into readable text, with or without its quotes.

Pull every value stored under a given key name, wherever it appears in the document.

Explore JSON as a collapsible tree, with node counts, depth and located errors.

Build a mailto: link with subject, body, cc and bcc, encoded so nothing truncates.

Convert Markdown to HTML or HTML back to Markdown, with a live preview.

Escape text so it is treated as a literal inside a regular expression.

Break a regular expression into pieces and explain what each one does in plain English.

Build a regular expression from tested patterns, with anchors and flags, and try it against sample text.

Pull every match out of text, with capture groups, named groups and positions.

Test a regular expression replacement with capture groups and see the result live.

Split text on a regular expression and see each resulting part, empties included.

Test a regular expression against sample text with live highlighting and capture groups.

Compare two semantic versions by precedence, including prerelease ordering and caret or tilde ranges.

Lay a query out clause by clause with keywords capitalised, or strip it back to a single line.

Bundle files into a .tar archive in your browser, with ustar headers any tar can read.

List and extract the contents of a .tar archive in your browser, with header checksums verified.

Convert between chmod octal values and rwx permissions, with the command to copy.

Indent XML to reveal its structure, or minify it back to a single line.

Bundle several files into one ZIP archive in your browser, with nothing uploaded.

Look inside a ZIP file and pull out its contents, without uploading the archive.

Wrap text to a set width, or break it after every sentence, without splitting words.

Pull email addresses, links, numbers, hashtags, mentions, IPs or dates out of any text.

Replace text across a whole document, with whole-word, case and regex options.

Count total and non-empty lines in text, logs, CSV or code.

Generate placeholder paragraphs, sentences or words for mockups and layout testing.

Tidy Markdown source without changing a single thing about how it renders.

Build a Markdown link with the escaping and angle brackets handled properly.

Turn CSV or spreadsheet rows into a properly aligned Markdown table.

Build a linked table of contents from a Markdown document's headings.

Count paragraphs in any text, along with sentences, words and characters.

Remove repeated lines from a list, with options to sort, trim whitespace and ignore case.

Reverse text by character, word or line — including emoji and accents, handled correctly.

Count the sentences in any text, with words per sentence and the rest of the figures.

Turn any title into a clean, lowercase, hyphenated URL slug with accents stripped.

Sort lines alphabetically, numerically, by length, in reverse or shuffled.

Estimate how long a speech, presentation, podcast or script takes to say aloud — or how many words you need to fill a time slot.

Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case and kebab-case.

Strip extra spaces, blank lines, line breaks, smart quotes and unwanted characters.

Compare two blocks of text line by line and highlight what was added, removed and unchanged.

Score text with six readability formulas and see which sentences are dragging it down.

Count words, characters, sentences, paragraphs and estimated reading time as you type.

Convert between degrees, radians, gradians, turns, arcminutes and arcseconds.

Convert between square metres, square feet, acres, hectares and square miles.

Convert clothing sizes between UK, US and EU, with the chest or bust measurement each corresponds to.

Keep only the columns you need from a CSV, in the order you choose them.

Convert between cups, tablespoons, teaspoons, millilitres and fluid ounces.

Compare two CSV files by a key column and see which rows were added, removed or changed.

Convert CSV into an array of JSON objects, with delimiter detection and optional typing.

Convert between comma, tab, semicolon and pipe delimited files.

Convert CSV rows into XML records, with names and values escaped correctly.

Convert CSV rows into a YAML list, quoting values YAML would otherwise misread.

Check a CSV for ragged rows, duplicate headers and structural problems before importing it.

Open a CSV as a sortable, filterable table and see which rows are malformed.

Remove duplicate rows from a CSV, matching on the whole row or one column.

Sort CSV rows by any column, with numbers sorted numerically rather than as text.

Convert between bytes, kilobytes, megabytes, gigabytes and their binary equivalents.

Convert a Word document to clean semantic HTML, with headings, nested lists and tables.

Extract the text from a Word document, keeping headings, lists and table rows.

Convert between joules, kilowatt hours, calories, food Calories and BTU.

Convert between newtons, kilonewtons, pound-force and kilogram-force.

Convert between hertz, kilohertz, megahertz, gigahertz, rpm and beats per minute.

Convert between MPG (US), MPG (UK), L/100 km and km/L. Compare fuel economy figures from different countries with the correct conversion.

Strip HTML to readable plain text, keeping paragraphs, list markers and link URLs.

Convert a date between ISO 8601, Unix time, week dates and ordinal dates.

Convert JSON to XML or XML back to JSON, in either direction.

Convert JSON to YAML or YAML back to JSON, in either direction, with indent control.

Turn an array of JSON objects into CSV, flattening nested objects into dotted columns.

Check whether a year is a leap year, and see why the rule is more than divide by four.

Convert between millimetres, centimetres, metres, kilometres, inches, feet, yards and miles.

Convert numbers between binary, octal, decimal, hexadecimal and any base to 36.

Convert between watts, kilowatts, mechanical and metric horsepower, and BTU per hour.

Convert between pascals, bar, psi, atmospheres, torr and mmHg.

Convert between pixels, rem, em, points and physical units at 96 dpi.

Keep only the CSV rows matching a condition on one column.

Convert a shoe size between UK, US men's, US women's, EU and foot length in centimetres.

Convert between km/h, mph, metres per second and knots.

Convert between Celsius, Fahrenheit and Kelvin with the formulas shown.

Convert text to binary, hex, decimal or octal bytes, and back again, in UTF-8.

Turn plain text into HTML paragraphs, escaping the text and linking URLs.

Convert between milliseconds, seconds, minutes, hours, days, weeks and years.

Convert between newton metres, pound-feet, pound-inches and kilogram metres.

Convert Unix timestamps to human dates and back, in local time and UTC, with ISO 8601 output.

Convert between litres, millilitres, cubic metres, US and imperial pints, quarts and gallons.

Find the ISO week number and day of the year for any date, with the edge cases explained.

Convert between grams, kilograms, tonnes, ounces, pounds, stones and tons.

Turn repeating XML records into CSV rows, finding the record element for you.

Convert YAML to XML or XML back to YAML, with attributes and type handling you control.

Find the date a number of days, weeks or months before or after another date.

Calculate exact age in years, months and days, plus total days and the next birthday.

Calculate area, perimeter and volume for circles, rectangles, triangles and common solids.

Scale width and height while keeping the aspect ratio, and identify the ratio itself.

Find the mean, median, mode, range and standard deviation of a list of numbers.

Estimate how long a battery will last from its capacity and the current a device draws.

Work out the document size with bleed, the safe area inside the trim, and the finished size after cutting.

Calculate body mass index from height and weight, in metric or imperial units.

Estimate resting metabolic rate and daily calorie needs from height, weight, age and activity.

Decode the three-digit code on a ceramic capacitor into picofarads, nanofarads and microfarads.

Work out a monthly car payment from price, deposit, trade-in, tax, fees and APR, with the total interest shown.

Project savings or investment growth with compounding and optional monthly contributions.

Work out the concrete volume for a slab, footing or column, in cubic metres and yards.

Count the days, weeks and months between two dates, with and without weekends.

Project an asset's value year by year using straight-line or declining balance depreciation.

Work out a sale price from a discount percentage, and how much is saved.

Find the great-circle distance and bearing between two sets of coordinates.

Work out what an appliance costs to run, per day, month and year, from its wattage.

Work out what charging an electric car costs, per charge and per mile or kilometre.

Estimate an electric car's real range from battery size, efficiency, temperature and the charge you keep in reserve.

Raise numbers to a power, take any root, and calculate logarithms.

Work out force from mass and acceleration, or weight from mass under gravity, in newtons and pounds-force.

Add, subtract, multiply or divide two fractions and simplify the result.

Estimate the fuel cost of a journey from distance, economy and fuel price.

Find the greatest common divisor and lowest common multiple of several numbers.

Divide a length by the golden ratio, or extend it, with a sequence of proportional steps.

Work out gravel, mulch, sand or topsoil needed by volume and weight, with bag counts.

Work out training heart rate zones from age and resting heart rate.

Compare healthy weight ranges for your height across several established formulas.

See what an amount is worth after inflation over a number of years.

Work out bread ingredient weights from baker's percentages, including hydration, salt, yeast and starter.

Estimate jet lag recovery from the time zones crossed and direction, with a pre-adjustment schedule.

Work out how many packs of laminate or vinyl flooring a room needs, with a cutting allowance.

Work out the series resistor an LED needs, with the nearest standard value and its power rating.

Find a line height and column width for a font size, from the number of characters per line.

Calculate the monthly repayment, total interest and total cost of a loan from amount, rate and term.

Calculate board feet and cost for timber, or the number of studs a wall needs at a given spacing.

Split a daily calorie target into protein, carbohydrate and fat, by ratio or by body weight.

Monthly mortgage payment including tax and insurance, with total interest over the term.

Solve for voltage, current, resistance or power from any two known values.

Convert an oven temperature between Celsius, Fahrenheit, gas mark and fan-assisted settings.

Calculate overtime pay at time-and-a-half or any multiplier, with total weekly pay.

Estimate how much paint a room needs, allowing for coats, doors and windows.

Convert any standard paper size between millimetres, inches, points and pixels at a chosen resolution.

Work out a percentage of a number, what percentage one number is of another, and percentage change.

Work out pressure from a force and a contact area, in pascals, bar, psi and atmospheres.

Check whether a number is prime and break it into its prime factors.

Work out the printable area and content width left on a page after margins and binding gutter.

Work out how large an image can be printed at a given resolution, in inches, centimetres and standard photo sizes.

Combine two event probabilities, and find the chance of at least one occurrence over repeated trials.

Solve ax² + bx + c = 0, with the discriminant and vertex shown.

Simplify a ratio, scale it up, or solve for a missing value.

Work out how much food to cook for a number of people, by course and appetite.

Scale a recipe up or down by servings, rewriting every quantity as a fraction a kitchen can measure.

Read a resistor's value from its colour bands, with tolerance and the range it may fall in.

Find the pixel dimensions and megapixels needed to print at a given size and resolution.

Project a retirement pot from monthly contributions, and what it might pay out.

Work out roof area from the footprint and pitch, in squares and bundles, with a waste allowance.

Calculate a room's floor area, wall area and volume in metric and imperial units.

Convert between spindle RPM, cutting speed, surface speed and pulley ratios.

Work out pace, finish time or distance for a run, with splits for common races.

Add tax to a net price or strip it out of a gross price at any rate.

Evaluate expressions with brackets, powers, roots, logs, trigonometry and factorials, in degrees or radians.

Work out simple interest and the final balance from principal, rate and time.

Solve for speed, distance or time, with pace per kilometre and per mile alongside.

Work out stair rise, going and total run, and check them against building regulations.

Work out how many tiles a floor or wall needs, including a wastage allowance.

Work out a tip and split the bill between any number of people.

Compare two tire sizes for diameter, sidewall, circumference and the speedometer error the change causes.

Work out torque from a force, a lever length and the angle it is applied at, in N·m and lb·ft.

Add up a trip's cost from flights, accommodation and daily spending, with a contingency and a per-day figure.

Work out nights, days and the annual leave a trip actually costs, from departure and return dates.

Build a modular type scale from a base size and ratio, in pixels and rem, with line heights.

Compare products by price per unit to find which is genuinely cheaper.

Work out variance, standard deviation, quartiles and outliers from a list of numbers.

Calculate the output voltage of a two-resistor divider, with current draw and loading advice.

Count working days between dates, or find the date a number of working days away.

Generate Code 128, EAN-13, EAN-8, UPC, Code 39 and ITF-14 barcodes as PNG or SVG.

Generate every favicon size from one image, including favicon.ico and the head snippet.

Create QR codes for links, WiFi networks, contacts, email, SMS or plain text.

Find how many units you must sell to cover fixed costs, and the revenue that represents.

Design a business card and export a print-ready PDF with bleed, a safe area and crop marks.

Calculate the compound annual growth rate between a starting and ending value.

Work out commission on sales, with a base salary and an optional tiered rate above target.

Preview email HTML at desktop and phone widths, with images blocked, and check it against client limitations.

Build an HTML email signature with inline styles that survive Outlook and every other client.

See where a subject line is cut off in common clients, and what in it reads as spam.

Create a professional invoice with line items, tax and totals, and download it as a PDF.

Apply a markup to a cost to get the selling price and resulting margin.

Work out what a meeting costs in salary time, including the true cost of employment.

Calculate gross profit, margin and markup from cost and selling price.

Read a QR code or barcode from a photo, a screenshot or the camera, and see what it contains before acting on it.

Send a priced quote with itemised work, tax and an expiry date, as a PDF.

Produce a receipt confirming a payment, with items, tax and the amount paid.

Calculate return on investment as a percentage, plus annualised return over a holding period.

Convert between hourly, daily, weekly, monthly and annual pay.

Re-indent minified SVG markup so it can be read and edited.

Collapse an SVG onto one line and cut its file size, with a preview.

Strip editor metadata, comments and excess precision from an SVG, with a live preview.

Generate Article or BlogPosting JSON-LD with author, dates and image.

Generate BreadcrumbList JSON-LD so results show a path rather than a bare URL.

Generate a rel=canonical link tag, with a check that the URL is suitable.

Build FAQPage JSON-LD from your questions and answers, ready to paste into a page.

Check a page's heading outline for skipped levels, duplicates and missing h1.

Generate hreflang link tags for multilingual and regional versions of a page.

Check the alt text on a page's images, including the difference between missing and decorative.

Check an image's size, dimensions, format and filename against what a web page actually needs.

Check JSON-LD structured data against the properties search engines actually require.

Count word and phrase frequency in a text, with density percentages.

Generate LocalBusiness JSON-LD with address, phone, hours and geo coordinates.

Generate title, description, canonical, Open Graph and Twitter Card tags with live length checks.

Generate Open Graph meta tags so links to your page preview correctly when shared.

Generate Product JSON-LD with price, availability, brand and rating.

Build a robots.txt file, including an optional opt-out for AI training crawlers.

Test whether a URL is allowed for a given crawler, and check a robots.txt for mistakes.

Preview how a page's title and description may appear in search results.

Check an XML sitemap for structural errors, bad dates, wrong hosts and the published limits.

Generate Twitter/X card meta tags for large-image or summary link previews.

Turn a list of URLs into a valid XML sitemap with lastmod and optional fields.

Encode text to Base64 or decode Base64 back to text, with UTF-8 and URL-safe support.

Decrypt a file encrypted here, using the password it was encrypted with.

Encrypt any file with AES-256-GCM and a password, entirely in your browser.

Hash any file with SHA-1, SHA-256, SHA-384 and SHA-512, and compare against a published checksum.

Sign a message with a secret key using HMAC-SHA256 and related algorithms.

Decode a JSON Web Token to inspect its header, payload, expiry and claims.

Generate an MD5 hash of any text, with a plain account of what MD5 is and is not good for.

Estimate how long a password would resist an offline attack, and why.

Generate cryptographically random tokens with a chosen alphabet, and see their entropy.

Generate an RSA key pair in the browser and export it as PEM or JWK, for signing or encryption.

Generate strong random passwords using the browser's cryptographic random number generator.

Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text using the Web Crypto API.

Generate SHA3-224, 256, 384 and 512 hashes, and SHAKE output of any length, from text or a file.

Encrypt and decrypt text with AES-256-GCM and a password, entirely in your browser.

Generate random version 4 UUIDs in bulk, with uppercase and no-hyphen options.

Check a UUID is well-formed and find out what its version actually reveals.

See your screen size, user agent, device pixel ratio, time zone and browser capabilities.

Check whether copying and pasting work in your browser, and see why when they do not.

Set a timer for any length, with presets, a progress bar and an alert when it finishes.

Test every key on your keyboard and see the key, code and keyCode each one sends.

Check your microphone works, see the live input level and waveform, and set your gain.

Test mouse buttons, scroll and movement, measure polling rate and click speed, and diagnose a double-click fault.

A plain text scratchpad that saves itself in this browser as you type.

Check whether browser notifications work, and find which layer is blocking them.

A focus timer that cycles between work sessions and breaks, with adjustable lengths.

Pick fairly from a list, generate random numbers, or shuffle items into a random order.

Test left and right channels separately with tones from bass to treble.

Time anything to a tenth of a second, with lap splits you can copy out.

See one moment across several time zones, with working hours marked for each.

A simple checklist that remembers itself in this browser, with no account.

Test a touchscreen for dead zones and check how many fingers it tracks at once.

Check your camera works, see its resolution and frame rate, and capture a still.

Build APA, MLA, Chicago or Harvard citations for websites, books and journal articles.

Work out the exam mark you need to reach a target grade for the course.

Calculate a weighted grade point average from course credits and grades.

Edit HTML, CSS and JavaScript together and see the page they make.

Check text and background colours against the WCAG 2.1 contrast requirements for AA and AAA.

Generate keyframes and the animation shorthand for common effects, with live preview.

Set border width, style, colour and per-side visibility, and copy the CSS.

Round each corner independently, including elliptical corners, and copy the CSS.

Build a box-shadow with live preview and copy the CSS, including inset and spread.

Design a button — colours, padding, radius, border and shadow — and copy the CSS.

Clip an element to a polygon, circle or ellipse and copy the clip-path CSS.

Stack blur, brightness, contrast, saturation, hue and more, and copy the filter.

Set direction, wrapping, alignment and gap, watch the layout respond, and copy the CSS.

Build a frosted-glass panel with backdrop blur, translucency and border, and copy the CSS.

Build linear and radial CSS gradients visually and copy the generated background property.

Build a grid with columns, rows and gaps, preview the tracks, and copy the CSS.

Write CSS against a fixed piece of markup and see the result as you type.

Generate the paired light and dark shadows behind the soft-UI look, and copy the CSS.

Build a text-shadow with live preview on real text, and copy the CSS.

Combine translate, scale, rotate and skew, see the result live, and copy the transform.

Convert colours between HEX, RGB and HSL with a live preview and copyable CSS values.

Write HTML and see it render as you type, in a sandboxed frame.

Look up any HTTP status code, what it means and what it usually indicates in practice.

Run JavaScript in a sandboxed frame and read the console output on the page.

Find the MIME type for a file extension, or the extensions for a MIME type.

Compare the three kinds of URL encoding, decode escaped text, and see which characters differ.

Turn a list of names and values into a correctly encoded query string.

Build a URL from a base address and named parameters, with encoding handled for you.

Strip utm, gclid, fbclid and other tracking parameters from one URL or a whole list.

Percent-encode text for safe use in URLs, or decode an encoded URL back to readable text.

Remove named parameters from a URL, or a list of URLs, keeping the rest intact.

Break any URL into protocol, host, port, path, query parameters and fragment.

Check whether a URL is well-formed, and see exactly what is wrong when it is not.

Break a user agent string into browser, engine, operating system and device.

Build campaign tracking URLs with correctly encoded utm_source, medium, campaign, term and content.