Text & test data tools
Find text problems and test input boundaries.
Choose a check
Inspect invisible or ambiguous characters, recover supported encoding mistakes, or generate hostile and exact-length strings. These browser tools support text-input QA; generated cases are examples, not proof that an application is secure. Use active payloads only against systems you may test.
Tools in this collection
Hidden Character Checker
Runs in browser- Two strings look identical but behave differently? Find what's hiding in them.
- Code fails on text that looks fine? Find invisible characters.
- Look-alike letters in a domain or name? Spot homoglyphs.
- Count length in characters, bytes and code units.
- Pasted from Word? Clean NBSPs, BOMs and zero-width spaces.
Find invisible and look-alike characters, count length every way, clean text.
Naughty Strings List
Runs in browser- Find inputs your form probably wasn't expecting.
- Test a form with 158 inputs it may not expect.
- Check fields against SQL, XSS and CSV injection strings.
- Try Unicode, emoji and right-to-left text in your UI.
- Copy test strings as JSON, CSV or code.
158 hostile test strings that say what they test, copied as JSON, CSV or code.
Exact-Length String Generator
Runs in browser- Test a field right at its length limit, and just beyond it.
- Field limit is 255? Test 254, 255 and 256.
- Limit in bytes, not characters? Generate exact UTF-8 lengths.
- See where text gets cut with a counterstring.
- Test emoji and accents that take more than one byte.
Strings of an exact length in characters or bytes, limit sets and counterstrings.
Mojibake Fixer
Runs in browser- Your text turned into strange symbols. See whether it can be recovered.
- Seeing é instead of é? Recover the original text.
- CSV opened with the wrong encoding? Fix the garbled text.
- See which characters were lost and cannot come back.
- Find out which encoding mix-up caused the damage.
Turn garbled UTF-8 text back into what was written, and see what was lost.