Base64 Decode
Decode base64 strings back into readable text, correctly handling UTF-8 and Unicode, with a clear explanation of anything it cannot parse.
Updated September 2026 · Written and verified by Akash Pandey
Base64 Decode
How to use the decoder
- Paste a base64 string into the box.
- Click Decode - valid strings become readable text instantly.
- If the output looks wrong, try the "interpret as UTF-8" toggle; the tool also explains why a string failed when it cannot be decoded.
Frequently asked questions
What does "cannot decode" mean?
The string contains characters base64 does not define (like "=" in the middle), is the wrong length, or produced invalid UTF-8 after decoding. The tool names which case it hit.
Why does decoded emoji show as garbage?
If the original was broken UTF-8 or a different encoding, bytes may be invalid. The tool decodes as UTF-8 by default, which covers nearly all real-world strings.
Can I decode with line breaks in the input?
Yes - whitespace is ignored automatically, which makes pasting wrapped base64 painless.
Is base64-decode the reverse of base64-encode?
Yes. Decoding the output of the encoder reproduces the original text exactly, including Unicode.
Is it private?
Fully - decoding runs in the browser with no network requests.
Why do I get an error when decoding Base64?
Base64 strings must contain valid characters (A-Z, a-z, 0-9, +, /, and = for padding) and have a length divisible by 4. Extra characters or invalid padding cause decoding errors.
Can I decode Base64 data URLs?
Yes. You can paste standard data URLs (e.g., data:text/plain;base64,...) and extract the decoded content.
Does this tool run client-side?
Yes. All Base64 decoding executes in your browser sandbox, keeping private tokens and sensitive keys off third-party servers.