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Base64 Image Decoder

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Decode Base64 strings back to viewable images with preview

See what’s hiding inside that Base64 blob

You’re digging through an API response and there’s this enormous Base64 string sitting in an image field. Or you’re inspecting a stylesheet and find a background-image with a data URI that goes on for 200 lines. What does it actually look like? Paste it here and find out.

The tool renders the image right in your browser. It figures out the format automatically, PNG, JPEG, GIF, WebP, or SVG, by checking the magic bytes at the start of the decoded data. You don’t even need to include the data:image/png;base64, prefix (though it works fine if you do).

Just paste and preview

Drop in the raw Base64 string or a full data URL. Click decode. The image appears. That’s it. You can also copy the complete data URI if you need it in that format.

Real situations where you’ll need this

Look, nobody decodes Base64 images for fun. Here’s when it actually matters:

API debugging. Your image upload endpoint returns a Base64 preview and you need to verify it’s the right image before wiring up the frontend. Way faster than writing code to render it.

Database forensics. Someone stored user avatars as Base64 text in a PostgreSQL column (it happens more than you’d think). You need to eyeball a few of them to check the migration worked.

Email template work. HTML emails embed images as Base64 to dodge the “images blocked by default” problem. When something looks wrong, decoding the strings tells you if it’s the image or the layout.

Broken images. Your app shows a broken image icon. Is the Base64 data corrupted, or is your rendering code the problem? Decode it here, if it looks fine, the bug is in your code.

Format detection

The decoder inspects the first few bytes after decoding to identify the format:

  • PNG: starts with the PNG signature (89 50 4E 47)
  • JPEG: starts with FF D8 (JFIF or EXIF header)
  • GIF: starts with GIF87a or GIF89a
  • WebP: RIFF container with WEBP marker
  • SVG: detected by XML/SVG content patterns

Animated GIFs play their animation in the preview. Everything happens client-side, your data stays in your browser.

To convert an image file to Base64, use the Base64 Image Encoder. For plain text Base64 (not images), the Base64 Decoder is what you want.

FAQ

Do I need the data URI prefix?

Nope. Paste the raw Base64 and the tool auto-detects the image format and adds the correct prefix. Or paste the full data:image/...;base64,..., both work.

Is there a size limit?

No hard limit, but your browser has to render the image. A few megabytes is fine. A 20MB TIFF encoded as Base64 might make your tab grumpy.

What if the data is corrupted?

You’ll get an error message. Usually means the string got truncated somewhere, has invalid characters, or isn’t actually image data.

Privacy?

All client-side. The Base64 data never leaves your browser, no uploads, no server processing.

base64 image decoder preview data-url

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