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Drop an image or click to choose

PNG, JPEG, GIF, WebP, SVG, BMP — up to 30 MB. One image at a time.

The image is read and encoded entirely on your device — it never leaves your browser.

US and UK web teams inline images as data URIs to shave HTTP round-trips off the critical path. Webpack's asset-modules and Vite both inline files under a configurable byte threshold by default, and CSS-in-JS setups in React shops do the same for icons. Email is the other big driver. HTML newsletters built in Mailchimp or sent through SendGrid lean on inline images so a logo renders even when a recipient blocks remote content. Government services following the GOV.UK Design System and US federal sites under USWDS guidance keep small glyphs inline to cut requests. And because the encode runs in JavaScript, the source image never touches a server, which matters for screenshots, ID scans, or HIPAA and GDPR review.

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How image-to-Base64 conversion works

The whole conversion runs in your browser using the File API and the built-in btoa function — no codec library is downloaded and no server sees the image. Here's the pipeline, start to finish:

  1. You drop or select an image. The browser reads it as a Blob from your local disk, never copying the bytes to a server.
  2. The file is read in 1 MB chunks and each chunk's bytes are appended to a binary string. Chunking keeps large images from overflowing the JavaScript call stack.
  3. The binary string is passed to btoa, which maps every three bytes onto four Base64 characters drawn from the A–Z, a–z, 0–9, plus / alphabet.
  4. The file's MIME type (image/png, image/jpeg, and so on) is read from the File object and prepended as the data: prefix, producing a complete data:image/…;base64,… URI.
  5. The page assembles four outputs from that URI — the full data URI, the raw Base64 with no prefix, a ready-to-paste tag, and a CSS background-image snippet — each with its own copy button.

Why encode an image as a data URI?

  • Inlining a small logo or icon as a data URI removes a separate network round-trip, so the page or email renders its first frame a little sooner.
  • A page or stylesheet with its images inline is self-contained. It works offline, and you can copy it around without dragging a folder of assets along with it.
  • Many mail clients block linked remote images by default. Inline a logo as Base64 and it shows up the moment the message opens, no remote fetch required.
  • The encoding happens entirely in your browser, so sensitive images never travel to a third-party server. That covers screenshots, ID scans, and internal diagrams.

Common uses for Base64 images

Data URIs show up wherever an image is small enough that a separate request costs more than the ~33% size inflation Base64 adds. Three patterns come up constantly:

  • Inline CSS icons: a 1–2 KB sprite or icon dropped into a stylesheet as background-image: url(data:…) so the rule is fully self-contained.
  • Email signatures and newsletters: a logo embedded as an with a data URI src renders even when the client blocks remote images.
  • Build-tool inlining: bundlers like Webpack and Vite inline assets under a byte threshold automatically, and this tool lets you preview exactly what that output looks like.

What does a Base64 image look like?

Take a tiny 1×1 transparent PNG. Its raw bytes are only 67 bytes, but encoded it becomes the string iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNk+M8AAAMEAYC0aGgAAAAASUVORK5CYII=, and the full data URI is data:image/png;base64,iVBORw0KGgo…. Notice the encoded form is roughly a third larger than the original. That's the trade-off for making binary data safe to embed directly in text.

Does my image get uploaded anywhere?

No. The conversion uses the browser's File API and the native btoa function to encode the image entirely on your device. You can confirm it yourself: open your browser's developer tools, switch to the Network panel, and convert an image — the only requests you'll see are the page load and any ads. Nothing image-shaped is sent to a server, which is what makes this safe for screenshots, ID documents, and internal diagrams.

Why is the Base64 output larger than my original image?

Base64 represents every three bytes of binary data with four ASCII characters, so the encoded text is about 33% larger than the source file. The data URI size readout on this page shows the exact inflated length. That overhead is why data URIs make sense only for small images — inlining a 2 MB photo would bloat your HTML or CSS far more than a separate request would have cost. As a rule of thumb, inline images under roughly 4 KB and link to anything larger.

Which image formats can I convert?

Any format your browser recognises as an image works, because the tool reads the raw bytes rather than decoding the picture. That covers PNG, JPEG, GIF, WebP, SVG, and BMP. The MIME type is read straight from the file, so the data: prefix always matches the real format — a JPEG produces data:image/jpeg and an SVG produces data:image/svg+xml. SVG is worth a special note: it's already text, so for SVGs a URL-encoded data URI is often smaller than the Base64 version, though this tool emits the Base64 form for consistency.

Drop an image, copy the data URI or the snippet you need, and paste it into your HTML, CSS, or email template. Every byte stays on your device. No upload, no account, no server round-trip.