How to use the UTF-8 Validator
- Enter or paste your input in the box (or set the options, if the tool needs no input).
- Adjust the options to match what you need — the result updates as you type.
- Copy the result or download it, and keep editing if you want a different outcome.
What does this tool do?
Paste bytes in hex, decimal or binary. The checker follows the UTF-8 rules: correct lead and continuation bytes, no overlong forms, no surrogates and nothing past U+10FFFF. When the bytes are valid it also shows the decoded text.
Everything runs in your browser, so nothing you enter is uploaded or stored.
Why use it?
- Free, with no sign-up and no limits.
- Instant results as you type.
- Private — your data stays on your device.
Example
Input: 48 65 6C 6C 6F C3 A9
Result: Valid UTF-8 (7 bytes, 6 characters).
Privacy
Everything you type is processed in your browser. Nothing you enter is sent to our servers or stored by us. There's no account to create and nothing to install.
Frequently asked questions
What does “invalid byte” usually mean?
The data is probably in another encoding such as Latin-1, or was cut off in the middle of a multi-byte character.
Is the UTF-8 Validator free to use?
Yes. It is free, needs no account and has no daily limit.
Last reviewed by the M2Toolkit team.