CODDY Tool

Base64 Decoder

Decode Base64 back to text, with automatic format detection.

Turn Base64 strings back into text. Handles standard and URL-safe alphabets automatically, tolerates missing padding, and tells you when the data is binary rather than text.

Everything you enter stays in this browser tab. Nothing is sent to our servers, logged or stored.

This is one of the thingsEncoding Tooldoes — open it for everything else it supports.

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What Encoding Tool supports

Base64

  • Base64 encode
  • Base64 decode

URL

  • URL encode
  • URL decode

HTML

  • HTML entity encode
  • HTML entity decode

About Base64 Decoder

Base64 strings turn up constantly in development work — in configuration files, log entries, HTTP headers, API responses and JWT tokens. Decoding them is how you find out what a system is actually carrying around.

Both the standard alphabet and the URL-safe variant are detected automatically, and missing padding is repaired rather than treated as an error. Decoded bytes are interpreted as UTF-8, and if the data was never text at all — an image or a compressed blob — the tool says so instead of showing a screen of replacement characters.

How to decode Base64

  1. Paste your Base64 string

    Standard or URL-safe, with or without padding.

  2. Read the decoded text

    The result appears immediately.

  3. Copy the result

    Take it to your clipboard or download it.

Frequently asked questions

Do I need to say whether it is URL-safe?

No. The decoder detects - and _ characters and applies the URL-safe alphabet automatically, and it adds any missing padding for you.

Why does the output look like gibberish?

The original data was probably not text. Images, archives and encrypted blobs are all commonly Base64-encoded and have no meaningful text representation. Valid Base64 that decodes to nonsense is a strong hint you are looking at binary.

Can I decode a JWT?

Yes — paste the header or payload section, the parts before and between the dots. Both are URL-safe Base64 and decode to JSON. The signature is raw bytes and will not produce readable text.

Is my data sent to a server?

No. Decoding runs entirely in your browser, which matters given that Base64 strings frequently contain access tokens and credentials.

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Base64 Decoder is free to use with no account, no watermark and no usage limits. Last updated 14 August 2026.