Base64 to Image Converter
Paste a base64 string or data URL, preview the image it encodes, and download it as a file — decoded entirely in your browser.
- Free
- No account
- Runs in your browser
- Nothing uploaded
Paste a base64 string or data URL to decode it back to an image — all processing happens in your browser.
Runs entirely in your browser — your input is never uploaded, logged, or stored.Privacy policy
What is Base64 to Image Converter?
Base64 is a text encoding of binary data, and it is everywhere: tools like this site's Image to Base64 Converter turn image files into data URLs (data:image/png;base64,iVBOR...) so an image can travel inside HTML, CSS, JSON, or a database field. The reverse is just as common — you pull a base64 string out of a database, an API response, or an old email, and you want the actual image back. That is what this tool does.
You paste a base64 payload, with or without the data:image/...;base64, prefix. The tool validates it, decodes it back to the original image bytes, and shows you the preview right in the page. When the image looks right, you download it as a file with one click. The download keeps the image's real MIME type, so a PNG pasted as a data URL comes back as a .png file and a JPEG as a .jpg.
Decoding happens locally in your browser — the string is never sent to a server, so it is safe for base64 blobs that came from private or production systems. It is a lossless round trip: base64 is an exact encoding of the original bytes, so the decoded image is byte-for-byte identical to the image that was encoded.
A base64 image can be a bare payload or a data URL:
data:<mediatype>;base64,<payload>
The tool first strips the optional prefix and reads the MIME type from it. It then validates the payload against the base64 alphabet and decodes it to the original bytes. The reported byte length is the true decoded size — base64 strings are ~33% longer than the bytes they represent, so the file you download is smaller than the string you pasted.
When the input has no data:...; prefix, the MIME type can't be read from the string itself, so the tool detects it from the image's file signature (PNG, JPEG, or GIF) once the bytes are decoded. If the bytes match none of those signatures, it stays PNG and says clearly that the bytes weren't a recognised image, rather than guessing. If you know the type, paste the full data URL — it always carries the correct MIME type.
Worked examples
- iVBORw0KGgo= (the 8-byte PNG signature) → decoded to 8 bytes and downloaded as image.png
- data:image/png;base64,iVBORw0KGgo= → same image, prefix accepted, MIME image/png
- AA== (a single 0x00 byte) → decoded to 1 byte as image/png
How to use Base64 to Image Converter
- Copy the base64 string or data URL you want to turn back into an image.
- Paste it into the input box.
- The tool decodes it and shows the image preview and its size.
- If it looks right, click Download to save it as a file with the correct extension.
Common errors
- A corrupt or truncated base64 string — the payload contains characters outside the base64 alphabet or has invalid padding, so it cannot be decoded. Double-check you copied the whole string.
- A string that is valid base64 but is not an image at all — the bytes decode fine but don't start with a recognised image signature, so the tool can't present a preview. It still lets you download the unknown blob rather than pretending.
- A bare payload without a data:...;prefix and no way to detect the type — the tool checks the decoded bytes against known image signatures (PNG, JPEG, GIF); bytes that match none stay PNG but are flagged as not a recognised image. Paste the full data URL if you need a specific type.
FAQ
Where does my base64 string go?
Nowhere. The string is validated and decoded entirely in your browser. Nothing is uploaded to a server, so it is safe to decode base64 blobs that came from private databases or production systems.
Do I need to include the data:image/png;base64, prefix?
No. The tool accepts the bare base64 payload on its own and as a full data URL. The difference is the MIME type: a full data URL carries the correct type in its prefix, while a bare payload has its type detected from the image's file signature after decoding. If the bytes match no known signature, the type stays PNG and the tool flags that the bytes weren't a recognised image.
Will the decoded image look exactly like the original?
Yes. Base64 is an exact, lossless encoding of the original bytes, so decoding it reproduces the image byte-for-byte. The only thing that changes is the file wrapper (the download's extension), never the pixels.
Why is the downloaded file smaller than the string I pasted?
Base64 inflates binary data by about 33% as it encodes it into text, so the reverse is true when you decode. A base64 string represents bytes that are roughly three-quarters of its own length, and the downloaded image is those original bytes.
How is this different from the Image to Base64 Converter?
The two tools are the reverse of each other. Image to Base64 Converter turns a file into a data URL for embedding; this tool turns a base64 string or data URL back into a downloadable image file.
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