Utilities

Base64 Decoder

Paste a Base64 string (with or without the data URL prefix) and download the original binary file. Useful for recovering images embedded in emails, JSON APIs, or HTML source.

Drop your file here

or click to choose from your device

Supported: txt · Max 10 MB

txt · 10 MB max

Going deeper

Recovering files from Base64

Base64 encoding is everywhere. APIs return images as Base64 strings to avoid binary responses. Email attachments can be Base64-encoded in the message body. JSON-LD embedded images use data URLs. Some legacy systems embed everything as Base64. Decoding back to a usable file is the workflow this tool supports.

The most common source of confusion is the data URL prefix. A data URL looks like data:image/png;base64,iVBORw.... The prefix tells us the MIME type, so we can save the decoded file with the correct extension. A plain Base64 string (just the iVBORw... part) doesn't carry MIME info, so we save it as .bin and you rename it based on what you know the content is.

If the decoded file doesn't open, the most likely cause is a truncated input string. Base64 is sensitive to length — drop one character and the whole decode breaks. Always copy the entire string from a trusted source; if you're pasting from an email, make sure your email client didn't word-wrap the string.

What you get

Features

  • Accepts plain Base64 or data URL

  • Auto-detects output MIME type from data URL prefix

  • Falls back to .bin if no MIME detected

  • Files deleted immediately after processing

Step by step

How to use

  1. 1

    Paste a Base64 string into the text area.

  2. 2

    Click Decode.

  3. 3

    Download the resulting file.

Your privacy

How this tool handles your file

Your input string is processed in memory and never stored on disk. Decoded output is returned to you immediately.

Read more about our security practices or see our privacy policy.

Frequently asked

Common questions

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