Base64 to Image Converter

Both — with or without the data:image/...;base64, prefix.

You'll see a clear error if the Base64 data can't be decoded into a valid image.

No — Base64 is just a way to represent binary data as plain text; it provides zero security or confidentiality. Anyone can decode a Base64 string back to the original file instantly, which is exactly what this tool does.

PNG, JPG, GIF, WebP, BMP, and SVG. Format is detected from the actual decoded data (binary magic bytes for the raster formats, the <svg> tag itself for SVG) rather than trusted from a file extension or declared MIME type, so it stays accurate even if the label is wrong.

Yes — Base64 has a second, URL-safe variant (using - and _ instead of + and /, usually with the padding = characters left off) that's what JWTs and many APIs actually produce. This is normalized automatically before decoding, so you can paste either variant directly.

Base64 has a fixed, unavoidable overhead: it represents every 3 bytes of the original binary data as 4 text characters, which works out to roughly 33% larger than the original file. That's not a bug or inefficiency in this tool — it's inherent to how Base64 encoding works.

For a handful of very small icons, it can be reasonable. For anything bigger, it's generally a bad trade today: the ~33% size overhead makes your HTML/CSS heavier, and the browser can no longer cache the image separately — it has to re-download every time the page does. The original justification (working around old browsers' limited simultaneous-connection caps) has also mostly disappeared now that HTTP/2 lets browsers transfer many files efficiently over one connection.

The most common causes: incorrect or missing padding, an invalid character that isn't part of the Base64 alphabet, or — if you've concatenated two separately-padded Base64 strings — a stray = character now sitting in the middle instead of only at the end. Standard vs. URL-safe charset differences are handled automatically here, so that specific mismatch shouldn't be the cause.

No — decoding happens entirely in your browser. Nothing you paste is sent to a server.

Yes — our Image to Base64 tool does the reverse direction, including SVG files, so both directions are covered.

In JavaScript, the same approach this tool uses: atob(base64String) to get the raw binary as a string, copy it into a Uint8Array byte-by-byte, then wrap that in a Blob with the right MIME type (or skip straight to new Image() with a data:image/...;base64,... string as the src, if you just need to display it). In C#, it's a single call: Convert.FromBase64String(base64String) returns the raw bytes directly, which you can write straight to a file with File.WriteAllBytes. Most other languages have an equally direct built-in Base64 decoder — the image-specific part is just knowing what to do with the resulting bytes.

Yes — once a valid image decodes successfully, a Download button appears next to the preview, saving it as a real image file with the correct extension.

Not with this tool — it's scoped to image formats specifically (PNG, JPG, GIF, WebP, BMP, SVG). Base64-encoded PDFs are a genuinely different, common need, but we don't have a dedicated tool for that yet.