RegexProofDescribe the pattern. Get a working regex — with safety callouts.
Plain-English to regex with part-by-part explanation, ECMAScript vs PCRE traps, and ReDoS heuristics. Decision-support for engineers — not a completeness guarantee.
For developers who need a reliable regex fast — and want the dialect and ReDoS traps flagged.
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Key Takeaways
- ECMAScript vs PCRE dialect traps called out with examples.
- ReDoS / catastrophic-backtracking heuristics for application regex.
- Subscribe for Pro runs; Free tier for light daily use. Not a formal verifier.
Dialects differ. Patterns break quietly.
Decision-support themes — not a completeness guarantee or formal proof.
RegexProof — definition
RegexProof reviews regular expressions for ReDoS and dialect pitfalls with deterministic heuristics plus optional model-assisted explanations — not a completeness guarantee.
What this is NOT
- Not a law firm, GRC platform, or ISO certification body.
- Not a guarantee that drafted policies will satisfy every regulator or auditor.
- Not a formal verifier — treat generated regex as drafts under engineer review.
Controller / Processor — When packs mention privacy roles, we use GDPR Art.4 labels: Controller and Processor (decision-support only).
Patterns look fine. Production hangs later.
Dialect traps
Lookahead, possessive, and Unicode classes differ across ECMAScript vs PCRE engines.
ReDoS risk
Nested quantifiers on untrusted input can stall event loops and APIs.
Opaque one-liners
Hand-written regex without part-by-part explanation is hard to review safely.
Issues after ship
Timeouts and false matches often appear only under adversarial or messy data.
Describe. Forge. Review.
Plain-English to regex with safety callouts — review before production.
Working pattern draft
A dialect-aware regex starting point for your language flavor.
Part-by-part explanation
Readable breakdown so reviewers can challenge assumptions.
ReDoS heuristics
Flags nested quantifiers and catastrophic backtracking shapes.
Dialect traps
ECMAScript vs PCRE differences called out — decision-support, not a proof.
Everything you need to forge safer regex
Built for engineers who need dialect and ReDoS callouts without a research rabbit hole.
NL description to regex
A dialect-aware regex starting point for your language flavor.
Pick your language flavor
Readable breakdown so reviewers can challenge assumptions.
Part-by-part explanation
Flags nested quantifiers and catastrophic backtracking shapes.
Edge cases called out
ECMAScript vs PCRE differences called out — decision-support, not a proof.
From description to safer pattern in 3 steps
Describe
Write the match intent in plain English and pick a dialect.
Forge
Generate a candidate regex with explanations and heuristics.
Review
Test against samples; keep engineers for adversarial cases.
Describe. Forge. Review.
Plain-English to regex with safety callouts — review before production.
Dialect traps
Lookahead, possessive, and Unicode classes differ across ECMAScript vs PCRE engines.
Working pattern draft — A dialect-aware regex starting point for your language flavor.
Try it on this page
or generate below.
Saved history
Built for early adopters
Built for solo founders and small teams — early access, no public case studies yet. When we publish quotes, they will be consented and attributed; we do not invent names, logos, or outcome metrics.
Honest boundaries
RegexProof is a drafting aid: customize, fuzz, and review before shipping to untrusted input.
Simple plans that scale
All paid plans include
- Natural language to regex studio
- Dialect trap callouts
- ReDoS heuristics (decision-support)
- Email support on paid plans — no hidden add-ons for core studio use
- Limited daily AI runs (10/day · 50/mo)
- Studio demo (no extra LLM fee)
- AI included: 300 gens/mo · fair use (gpt-4o-mini)
- No separate ChatGPT subscription required
- Priority support · 2 months free with yearly
Feature comparison
What each plan includes — quotas reflect the enforced fair-use limits.
| Dimension | Free | Pro | Enterprise |
|---|---|---|---|
| Usage | |||
| AI runs | 3/day · 15/mo | 40/day · 300/mo | 200/day · 3,000/mo |
| Report export | Watermarked | Clean export | Clean export |
| Audit log | Not included | ✓ Included | ✓ Included |
| Product | |||
| NL description to regex | ✓ Included | ✓ Included | ✓ Included |
| Pick your language flavor | ✓ Included | ✓ Included | ✓ Included |
| Part-by-part explanation | ✓ Included | ✓ Included | ✓ Included |
| Edge cases called out | ✓ Included | ✓ Included | ✓ Included |
| BYOK (your LLM key) | Not included | Not included | ✓ |
| SSO | Not included | Not included | Roadmap |
| Support & compliance | |||
| Support | Community | Priority | Custom SLA |
Already paid? Unlock Pro with your license
Licenses are issued manually after your payment is confirmed: we generate one per paid order and send it to the purchase email, typically within a few hours. Enter it below to activate Pro on this device — no account needed. Nothing yet? Write to lixingliangsy@163.com and reference your order email.
Your questions, answered
What does RegexProof generate?
A dialect-aware regex draft with part-by-part explanation, ECMAScript vs PCRE traps, and ReDoS heuristics — decision-support, not a formal verifier.
Is this legal advice or a certification?
No. Outputs are decision-support drafts. Have counsel and risk owners review before production. We do not claim ISO, CMP, or regulator certification.
Can I cancel anytime?
Yes. Self-serve plans cancel anytime; access continues until period end.
Do I need a credit card to start?
No. Start with email signup or Demo mode in the studio, then upgrade when ready.
Do I need my own ChatGPT / OpenAI subscription?
No for Free/Pro. AI runs are included in your plan (fair use) via our platform key. Enterprise can optionally bring your own OpenAI key (BYOK) — configure it at /settings (key stays server-side only).
What is Fair Use / what if I hit the AI limit?
Pro includes about 300 AI generations/month (and a daily cap) on gpt-4o-mini. If you hit the fair-use limit, Studio returns a mock/demo result until the daily or monthly reset — or upgrade / use Enterprise BYOK for heavier volume.
Is checkout secure?
Payments are processed by Waffo Pancake (merchant of record).
What happens after I pay?
You receive access confirmation; fulfillment is tracked via webhook + order logs.
Quick answers
- RegexProof turns a plain-English description into a working regular expression.
- You pick the target flavor: JavaScript, Python, Go, PCRE or Rust.
- Each part of the pattern is explained, with edge cases listed for you to test.
- Deterministic rules flag ReDoS risks and dialect pitfalls before you ship.
- Pricing starts at $0 (Free).
More questions
Which dialects?
Highlights ECMAScript (JS) vs PCRE-style differences that commonly surprise application code.
Is this a formal verifier?
No. Heuristics and decision-support only — not a mathematical proof of regex safety.
What is ReDoS?
Regular expression Denial of Service — catastrophic backtracking on crafted inputs.
Demo vs live?
Demo mode returns labelled samples; live AI narrative needs a configured key.
Primary sources?
ECMAScript specification notes, PCRE docs, and known ReDoS literature.
How it compares
| Dimension | Manual | RegexProof |
|---|---|---|
| Speed | Hours to days | Minutes per run |
| Consistency | Varies by person | Same ruleset every run |
| Output | Free-form | Structured, exportable result |
| Best for | Final sign-off | First-pass decision-support |
When not to use: Use qualified human review instead. The heuristics catch common patterns, but novel attacks may be missed.
- ecmascript vs pcre dialect traps 2026 — From the RegexProof blog.
- redos heuristics for application regex 2026 — From the RegexProof blog.
- Fleet launch notes — RegexProof ships in the LX AI Micro-SaaS fleet.
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