Base64 Decode
Decode Base64 strings back into readable text instantly.
Input is processed in your browser and is not uploaded.
Output
Results appear here.Add input to see a result.
Use this Base64 decoder to inspect encoded strings from APIs, headers, tokens, and configuration values. Invalid Base64 is reported clearly without uploading data. Lightweight, mobile-friendly, and built for quick repeat use.
Inspect encoded strings without guessing what they contain
Base64 strings show up in headers, tokens, data exports, and configuration values. Decoding them helps you verify whether a value is plain text, a JSON fragment, an image marker, or binary data. This decoder keeps the inspection local and reports invalid input clearly so you can separate bad padding from unreadable binary content.
Header inspection
Decode Basic auth test strings or copied header values while debugging local API calls.
Payload review
Check small encoded JSON snippets, webhook examples, or fixture values before adding them to docs or tests.
Encoding cleanup
Identify padding problems, accidental spaces, copied quotes, or URL-safe characters that need a different decoder.
A safer decoding routine
- 1Trim accidental whitespace from copied values before decoding.
- 2Decode once, then inspect whether the result is readable text or binary-looking data.
- 3If the result looks like JSON, validate it separately before trusting the structure.
- 4Do not paste credentials from production systems unless your local policy allows it.
Decode and verify
eyJ0b29sIjoiYmFzZTY0IiwicHJpdmF0ZSI6dHJ1ZX0={"tool":"base64","private":true}After decoding, the result can be sent to the JSON formatter or validator for a second pass.
Failure cases
- Missing or extra padding can make otherwise familiar strings fail.
- Some Base64 values represent binary files, so the decoded result may not be readable text.
- JWT segments use Base64URL and may omit padding by design.
FAQ
What can I decode with this tool?+
You can decode Base64 strings that represent text, including UTF-8 text.
Why does decoding fail?+
The input may include invalid characters, missing padding, or binary data that is not readable text.
Is Base64 decoding private?+
Yes. Decoding is done locally in your browser.