Image to Base64 Converter
Convert an image to a Base64 data URI and back, with ready-made snippets.
How do you convert an image to Base64?
Converting an image to Base64 turns its binary bytes into plain ASCII text you can paste straight into HTML, CSS, JSON, or any format that only accepts text — the output is a data URI like data:image/png;base64,iVBORw0KG... that browsers render as if it were a separate file, with no extra network request. This tool converts both ways — image to Base64 and Base64 back to image — entirely in your browser: the file never gets uploaded anywhere, so it works just as well with screenshots, logos, or images containing sensitive data. It auto-detects the image type (PNG, JPG, GIF, WebP, or SVG), produces the full data URI, the bare Base64 string, and ready-to-paste HTML, CSS, and Markdown snippets, and flags when the result is too heavy to reasonably embed.
How to use Image to Base64 Converter
- Drag your image into the upload zone or click to pick one from your device (PNG, JPG, GIF, WebP, or SVG).
- The tool instantly produces the full data URI, the bare Base64 string, and ready-to-paste HTML, CSS, and Markdown snippets.
- Copy whichever block you need with one click, or switch to the Base64 → Image tab to paste a data URI or Base64 string and preview or download the resulting image.
Common use cases
Inline a small logo or icon with no extra HTTP request
For small assets — a favicon, an email logo, a UI icon — embedding the data URI directly in HTML or CSS saves a full network round trip, which adds up fast on pages with many small graphics.
HTML emails where remote images get blocked
Most email clients block remote images by default. Embedding small graphics as Base64 inside the email's own HTML guarantees they render immediately, without waiting on the recipient to approve loading images.
Static prototypes and demos with no asset host
When building a quick static prototype or a CodePen, pasting the image as a data URI skips setting up asset hosting just for a mockup that will only live for a short while.
Inspecting an API response that returns Base64 images
Some APIs — image generation, OCR, digital signatures — return the result as bare Base64 inside a JSON payload. Paste that value into the Base64 → Image tab to see the actual picture without writing any code.
Recovering a data URI buried in legacy code
If you find a long `data:image/...;base64,...` string inside an old CSS file or a legacy component, paste it here to see the real image before deciding whether it's worth extracting to a standalone file.
Frequently asked questions
How do I convert an image to Base64 without uploading it anywhere?
Drag the file into the upload zone — the conversion happens entirely in your browser using the FileReader API, with nothing sent to a server. You can verify it yourself: disconnect from the internet after the page loads, and it keeps working exactly the same.
How much bigger does an image get after converting it to Base64?
About 33% bigger: Base64 represents every 3 binary bytes as 4 text characters. A 90 KB image becomes roughly 120 KB as Base64. The tool shows that exact math right next to the result.
When should I NOT use Base64 for an image?
Skip Base64 for anything over 100 KB, almost always. Once it's embedded in HTML, CSS, or JS, the browser can no longer cache it separately from the file that contains it — so it gets re-downloaded every time any other part of that file changes. Base64 also compresses worse than the original binary and blocks rendering until the whole document arrives. For photos, banners, or any normally-sized image, serve it as a standalone file with its own URL instead.
Which image formats does the tool detect when decoding a bare Base64 string?
PNG, JPG, GIF, WebP, and SVG — identified from the file's first bytes (its signature), not from a file extension you might not have. If you paste Base64 without a data: prefix and none of those signatures match, you can still download it as raw binary (.bin) to inspect with another tool.
Can I paste a full data URI into the Base64 → Image tab, or only bare Base64?
Both work. Paste a full data URI (`data:image/png;base64,...`) and the tool uses the type it already declares. Paste just the bare Base64 part, with no prefix, and it detects the type automatically by inspecting the decoded binary content.
Is it safe to convert a screenshot or document with sensitive information here?
Yes — every step, from reading the file to encoding and decoding, happens in your browser's memory, with no requests to any server and no storage. Close the tab and no trace of the image or the generated Base64 remains.