RE2
A fast and safe regular expression library that prevents performance catastrophes
- Vendor
- Also known as
- re2
Available worldwide
What is RE2?
RE2 is a C++ library providing regular expression matching with predictable performance guarantees. It avoids exponential backtracking by preventing constructs that require it, ensuring linear-time execution while supporting POSIX and most Perl regex syntax.
RE2 pricing
We don't have RE2's full plan breakdown yet (its pricing page resisted automated reading). Here's what we could confirm. Always check live pricing for exact numbers.
What RE2 does
The capabilities that matter for regex tools, normalised so it lines up with every alternative. “-” means we haven't confirmed it, not that it's missing.
- Redos resistant
- ✓
- Lookaround support
- ✗
- Backreferences
- ✗
- Unicode property escapes
- -
- Named captures
- -
- Multi pattern matching
- -
- Interface type
- Library
- Visualization
- -
- Code generation
- -
Platform & deployment
Independently observed- macOS
- Linux
- Windows
- Self-hosted
Integrations (1)
Independently observed- GitHub
Security & compliance
Known vulnerabilities: 0 (0 in the last 12 months) sourcea count reflects scale & disclosure, not quality
RE2 FAQ
Common questions about RE2, answered from independent, dated evidence.
What is RE2?
RE2 is a C++ library providing a thread-safe alternative to traditional backtracking regex engines like PCRE and Perl, prioritizing predictable performance and security over feature completeness. It is indexed under Regex Tools.
Source: https://github.com/pricing
Is RE2 free to use?
RE2 is open source, so it can be self-hosted and used at no licence cost. It is released under the BSD-3-Clause licence. Pricing changes often, so verify at source before relying on it.
Source: https://github.com/pricing
What platforms does RE2 support?
RE2 supports Windows, macOS, Linux and a command-line interface. Platforms we have not confirmed are simply not listed here rather than ruled out.
Source: https://github.com/pricing
Can RE2 be self-hosted?
Yes. RE2 can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.
Source: https://github.com/pricing
Is RE2 open source?
Yes. RE2 is published under the BSD-3-Clause licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.
Source: https://github.com/google/re2
Where is RE2 available?
RE2 is available worldwide. The vendor is headquartered in the United States.
Source: https://github.com/pricing
RE2 alternatives
Other regex tools we track, ranked by the same independent score.
- regex (Python module)Python regex engine extending the standard re module with additional featureslow · 43%
- PCRE2Pattern matching library with Perl 5 compatible syntaxlow · 29%
- HyperscanA high-performance C library for efficiently matching multiple regular expressions at oncelow · 31%
- RegExrTest regular expressions with real-time feedbacklow · 22%
- OnigurumaA C library for regular expression pattern matchinglow · 30%
- RegexBuddyA desktop tool for learning, creating, debugging, and managing regular expressionslow · 19%
The vioscaleAI score: one lens on the evidence
Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for RE2, not the verdict.
| Signal | Score | Weight | Contribution | Evidence |
|---|---|---|---|---|
| Release cadence | 83 | 0.07 | 5.6 | ✓ |
| Security score | 63 | 0.05 | 3.3 | ✓ |
| Dependent projects | 39 | 0.08 | 3.1 | ✓ |
| Stars | 75 | 0.03 | 2.5 | ✓ |
| Capabilities | 29 | 0.08 | 2.4 | ✓ |
| Development activity | 10 | 0.12 | 1.1 | ✓ |
| Integrations | 9 | 0.05 | 0.5 | ✓ |
| Security posture | 5 | 0.09 | 0.0 | - |
| Package downloads | 0 | 0.17 | 0.0 | - |
| Developer Q&A activity | 0 | 0.08 | 0.0 | - |
Computed . Re-weight it by intent, or see the full method.
All data & sourcesshow ↓
Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.
Activity
| Attribute | Value | Evidence |
|---|---|---|
| Commits last 30d | 1 | mediumsource · 2026-10-15 · 65% |
Adoption
Content
| Attribute | Value | Evidence |
|---|---|---|
| Faq | 6 items | mediumsource · 2026-09-10 · 68% |
Features
| Attribute | Value | Evidence |
|---|---|---|
| Capabilities | Backreferences: No · Interface type: library · Redos resistant: Yes · Lookaround support: No | mediumsource · 2026-10-15 · 60% |
Integrations
| Attribute | Value | Evidence |
|---|---|---|
| Count | 1 | mediumsource · 2026-08-19 · 60% |
Language
| Attribute | Value | Evidence |
|---|---|---|
| Primary | C++ | highsource · 2026-10-15 · 90% |
License
| Attribute | Value | Evidence |
|---|---|---|
| Spdx | BSD-3-Clause | highsource · 2026-10-15 · 95% |
Market
| Attribute | Value | Evidence |
|---|---|---|
| Availability | HqCountry: US · PrimaryMarkets: … · AvailabilityScope: global · AvailableCountries: … · NotAvailableCountries: … | highsource · 2026-08-19 · 75% |
Pricing
Release
Security
| Attribute | Value | Evidence |
|---|---|---|
| Disclosure policy | Yes | mediumsource · 2026-08-19 · 60% |
| Scorecard | 6.3 | highsource · 2026-10-15 · 90% |
| Vulnerabilities | Count: 0 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=pypi&package_name=google-re2&per_page=100 · Last 12m: 0 | highsource · 2026-10-15 · 90% |
| Trust center | https://github.com/security | mediumsource · 2026-10-15 · 60% |
Is RE2 the right choice for you?
Tell us the job, the constraints and what you weigh most, and we will rank RE2 against the rest of the regex tools we index, using the same dated evidence weighted your way.
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