Plain-English to regex
Describe what the text should match in a sentence. RegexProof handles the escaping, grouping, and quantifiers for you.
For developers
Describe the pattern,
Describe the pattern,
get a working regex.
Key Takeaways
- Describe the pattern in plain language, get a working regex instantly.
- Beyond generation: prove the regex is correct with test-case verification.
- Free to try; Pro plan for heavy daily use.
RegexProof turns a plain-English description into a correct regular expression for your language — with a part-by-part explanation and the edge cases you'd otherwise find in production.
Free tier: 10 forges / month
regexforge — JavaScript
You describe it
"a US phone number like (415) 555-2671 or 415-555-2671"
RegexProof returns
/\(?(\d{3})\)?[-.\s]?(\d{3})[-.\s]?(\d{4})/
# Part-by-part
# \(? optional "(" before area code
# \d{3} three-digit area code
# [-.\s]? separator: dash, dot, or space
Generates correct patterns for the flavors you actually ship
JavaScript
Python
Go
PCRE
Rust
Core capabilities
Regex, explained — not just generated
Four things RegexProof does so you can stop copy-pasting from Stack Overflow and start trusting the pattern.
Pick your language flavor
JavaScript, Python, Go, PCRE, or Rust — the same description yields the syntax that actually runs in your engine.
Part-by-part explanation
Every significant token is annotated in plain language, so you can read the pattern back and confirm it does what you meant.
Edge cases called out
RegexProof lists the inputs that will surprise you — international formats, missing separators, greedy matches — before they reach users.
How it works
From sentence to safe pattern in three steps
1
Describe what to match
Type the pattern in plain English and paste optional test strings — the ones that should match and the ones that shouldn't.
2
Pick a flavor
Choose JavaScript, Python, Go, PCRE, or Rust. The output is written in the syntax your runtime expects.
3
Forge & explain
Get a working regex, a part-by-part breakdown, and the edge cases to watch — ready to drop into code.
For developers
Patterns developers reach for
Real examples of what you can describe instead of writing the regex by hand.
US phone number
"A US phone number like (415) 555-2671 or 415-555-2671"
/\(?(\d{3})\)?[-.\s]?(\d{3})[-.\s]?(\d{4})/
Log line
"An ISO timestamp, then a level word, then a message"
/^(\d{4}-\d{2}-\d{2}T[\d:]+) (\w+) (.+)$/
URL slug
"Lowercase words joined by hyphens, 3 to 60 chars"
/^[a-z0-9]+(?:-[a-z0-9]+){2,59}$/
Email-ish
"Something@something.tld with a real TLD"
/^[^@\s]+@[^@\s]+\.[a-z]{2,}$/i
CSV field
"A field that may be quoted and contain commas"
/"([^"]*)"|([^,]+)/g
Strong-ish password
"8+ chars, at least one letter and one digit"
/^(?=.*[A-Za-z])(?=.*\d).{8,}$/
Pricing
Start free, upgrade when you ship
10 forges a month on the free plan. Unlimited with history on Pro — $19/mo.
Stop fighting the syntax
Describe the pattern. Get a working, explained regex.