Form inputs
Emails, phones, zip codes, and passwords — generated and explained so reviewers trust them.
See examples
The product
RegexProof
Describe a pattern in plain English and get a correct regular expression for your language — with a part-by-part explanation and the edge cases that bite in production.
5 languages
Explained output
$19/mo Pro
Input
"Extract the version like v1.2.3 or 1.2.3 from a string" Language: Go
Output
/(?:v)?(\d+)\.(\d+)\.(\d+)/ # Part-by-part # (?:v)? optional leading "v" # (\d+) major version (captured) # \. literal dot # (\d+) minor version (captured) # \. literal dot # (\d+) patch version (captured) # Edge cases # - "1.2" (no patch) won't match. # - "v1.2.3.4" matches only the first three groups.
What it does
Four jobs RegexProof does for you
Write the pattern in English
Skip the syntax lookup. Describe what the text should match — including optional test strings — and RegexProof builds the expression.
- Handles escaping, groups, and quantifiers
- Optional positive/negative test strings
- No more copy-paste from search results
Output for the engine you use
The same description yields syntax that actually runs in JavaScript, Python, Go, PCRE, or Rust — no manual translation between dialects.
- JavaScript · Python · Go · PCRE · Rust
- Flags and anchors matched to the flavor
- Copy-ready, drop into your code
Read it back before you ship
Every significant token is annotated in plain language, and RegexProof lists the edge cases to watch — so the pattern does what you meant.
- Part-by-part explanation
- 2–3 edge cases per pattern
- Promotes testing before deploy
Free vs Pro
What each plan includes.
| Capability | Free | Pro |
|---|---|---|
| Forges per month | 10 | Unlimited |
| Language flavors | All 5 | All 5 |
| Part-by-part explanation | ✓ | ✓ |
| Edge cases called out | ✓ | ✓ |
| Saved history | — | ✓ |
| Price | $0 | $19/mo or $190/yr |
Where RegexProof fits
Common places a generated, explained regex earns its keep.
Logs & text
Turn a line format into capture groups you can map straight into structs or rows.
See examplesReading regex
New to regex? The part-by-part breakdown is a working tutorial for any pattern.
View pricingProduct FAQ
JavaScript, Python, Go, PCRE, and Rust. The same description is rendered in the syntax each engine expects, including the right flags and anchors.
RegexProof produces a strong starting point, then explains each part and lists edge cases. We recommend running it against your real inputs — no generator removes the need to test against the strings you actually see in production.
Free includes 10 forges per month with full explanations. Pro is unlimited and saves your history so you can revisit and reuse past patterns. Pro is $19/mo or $190/year.
Describe your first pattern
Free to start — 10 forges a month, no card required.