How much larger does Base64 make an image?

About 33% larger, plus the data URL prefix. That overhead is the price of avoiding a separate request.

When should I inline an image?

For assets of a few kilobytes that appear on every page, or where external files are blocked, as in some email clients. Larger images are better linked.

Image to Base64

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

Runs in your browserNo account neededFree

Processing: This tool runs entirely in your browser. Your input and any file you open stay on your device — nothing is uploaded to a server.

How to use the image to base64

Choose an image to encode, or paste a data URL to decode.
Copy the data URL, or the ready-made img tag or CSS.
Keep it for small assets — link to anything larger.

About this tool

A data URL embeds an image directly in your CSS or HTML, saving a network request. That is a genuine win for a small icon, a single-file document or an email template where external images are blocked.

It is a loss for anything larger. Base64 inflates the data by about a third, the image can no longer be cached separately from the page, and it blocks whatever file it sits inside from finishing. Over roughly 5–10 KB, a normal image file is the better choice — and the tool warns when the result crosses 100 KB.

The reverse direction takes a data URL and gives you the image back as a file, which is handy when you find one embedded in someone else's stylesheet.

Common uses

Inlining a small icon in CSS.
Embedding an image in a single-file HTML document.
Recovering an image from a data URL in someone else's code.

Frequently asked questions

How much larger does Base64 make an image?: About 33% larger, plus the data URL prefix. That overhead is the price of avoiding a separate request.
When should I inline an image?: For assets of a few kilobytes that appear on every page, or where external files are blocked, as in some email clients. Larger images are better linked.

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