How to use
- Paste a Base64 string or a complete data URI into the input box, or press Load example to try a sample.
- Check the preview and the details: detected format, MIME type, dimensions and decoded size.
- Choose a download format. Original saves the exact decoded bytes; every other option converts the image in your browser.
- Download the file.
Turning Base64 text back into a picture
Images travel as Base64 whenever a channel only accepts text: data URIs in HTML and CSS, JSON responses from APIs, HTML email, database columns and log files. The encoded text is about one third larger than the binary file. Decoding reverses the process and gives you back the original bytes.
You can paste the bare Base64 string or the full data:image/...;base64, URI. Line breaks and spaces are ignored, and URL-safe Base64 (with - and _) is accepted as well. Decoding, previewing and converting all happen locally in your browser, so the image is never uploaded.
Recognising the format from the first characters
Every image format begins with a fixed byte signature, and those bytes always encode to the same leading Base64 characters. The tool checks the decoded bytes rather than trusting the MIME type in a data URI, so a mislabeled string is still identified correctly.
| Base64 starts with | Format |
|---|---|
iVBORw0KGgo | PNG |
/9j/ | JPEG |
R0lGOD | GIF |
UklGR | WebP (RIFF container) |
PHN2Zy or PD94bWwg | SVG |
Qk | BMP |
AAABAA | ICO |
SUkq or TU0A | TIFF |
JVBER | PDF, not an image: use Base64 to PDF |
Choosing a download format
Original writes the decoded bytes unchanged, which is the right choice when you only need the file. The other formats are produced by drawing the image onto a canvas and encoding it again:
- PNG is lossless and keeps transparency.
- JPEG fills transparent areas with white and uses the quality slider.
- WebP and AVIF usually give smaller files; AVIF is offered only if your browser can encode it.
- GIF is limited to 256 colours and keeps only the first frame of an animation.
- BMP, ICO and TIFF cover legacy software, favicons and print workflows.
- SVG wraps a raster image in an SVG file. It does not trace the picture into vector shapes.
Frequently asked questions
Why is my Base64 image not showing?
\/ or a literal \n, or data that is not an image at all. Remove the extra characters and paste again. The Base64 validator shows invalid characters and the detected content type.Do I need the data:image prefix?
Is my image uploaded to a server?
No. The page decodes and converts the image with JavaScript in your browser. Nothing you paste leaves your device.
Can it open HEIC or TIFF images?
Both formats are detected, but most browsers cannot display them, so the preview may be empty. You can still download the original file, and converting works when your browser is able to decode the image.