Text Validator
Validate text against length, format and content rules in one click — perfect for form testing and data checks.
What is Text Validator?
You're testing form input or batch-checking content against rules. Eyeballing 200 entries for length or character violations is impossible.
Paste your text, set rules, and get instant pass/fail with details.
If you're testing form validation, you replicate server rules in the browser. If you're QA-ing user input, you spot violations before storage. If you're auditing content batches, you catch outliers fast.
How to use Text Validator
Four steps. No setup, no signup.
Step 1
Paste your text
Step 2
Set validation rules
Step 3
See pass/fail and specific issues
Step 4
Fix and re-check
Example
Email format checked against a regex rule.
Input
alice@toolkno.com bob@ carol@example.org Rule: valid email
Output
✓ alice@toolkno.com ✗ bob@ (invalid format) ✓ carol@example.org
Why Text Validator is useful
- ✓
Replicate server-side form rules in your browser for testing.
- ✓
Combine length, character-type and regex rules in one pass.
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Each line gets validated independently for batch checks.
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Live updates — watch errors clear as you fix them.
Common questions
What can I validate?
Length ranges, character types, required keywords, format patterns.
Tip: Combine rules for thorough checks.
Does it support regex?
Most validators allow regex pattern rules.
Tip: Use for email or phone format checks.
Can I validate multiple lines at once?
Yes, each line gets validated independently.
Tip: Useful for batch input checks.
Does it explain failures?
Yes, each rule shows which line and why it failed.
Tip: Read the message before fixing.
Last reviewed: April 2026 · Free, browser-based, no signup.
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