comparison
voiddo regexlab vs regexr
Both test regular expressions in the browser using the JavaScript engine with real-time highlighting. voiddo regexlab ships a curated 30+ pattern library with individual test pages. regexr adds community sharing and an inline token reference. Here is when each makes sense.
use voiddo regexlab when…
- you need a ready-to-use regex for email, UUID, IBAN, JWT, semver, or 30+ other formats
- you want dedicated per-pattern test pages to validate your input immediately
- your test data is sensitive and you want zero server calls of any kind
- you want no account, no ads, and no signup
use regexr when…
- you want to save a pattern and share a permalink with a colleague
- you want the inline Reference panel that explains every character class and quantifier
- you want to browse community-shared patterns for inspiration
feature comparison
| feature | voiddo regexlab | regexr |
|---|---|---|
| Real-time match highlighting | ✓ yes | ✓ yes |
| JavaScript (ES2024) engine | ✓ yes | ✓ yes |
| Regex flags (g, i, m, s, u, d) | ✓ yes | ✓ yes |
| Capture group display | ✓ yes | ✓ yes |
| 30+ named pattern library | ✓ yes (email, UUID, IBAN, JWT…) | ✗ no built-in curated library |
| Individual pattern test pages | ✓ yes (30+ dedicated pages) | ✗ no per-pattern pages |
| Inline token Reference panel | ✗ no | ✓ yes (detailed token explanation) |
| Save pattern + permalink | ✗ no | ✓ yes (requires account) |
| Community shared patterns | ✗ no | ✓ yes (public library) |
| Data sent to server | ✓ never | only when saving a pattern |
| Account required | ✓ no | only to save/share |
| Ad-free | ✓ yes | ad-supported on free tier |
| Price | ✓ free | ✓ free (paid tier available) |
FAQ
Is voiddo regexlab an alternative to regexr?
Yes. voiddo regexlab is a free browser-only regex tester with real-time match highlighting, capture group display, and a library of 30+ named ready-to-use patterns — email, UUID, URL, IPv4, IBAN, JWT, credit card, semver, and more. Like regexr, it uses the JavaScript engine and runs entirely in your browser.
What does regexr have that voiddo regexlab does not?
regexr.com includes an inline Reference panel that explains each regex token as you type — useful when learning or debugging complex patterns. It also lets you save and share patterns with a permanent URL, and shows a community library of patterns submitted by other users. voiddo regexlab does not have these sharing or reference features.
What does voiddo regexlab have that regexr does not?
voiddo regexlab includes 30+ named patterns with individual test pages. Navigate to
tools.voiddo.com/regex/match-email-address/, match-uuid/, match-iban/, match-jwt/, match-semver/, or 25+ other pattern pages and test your input immediately without writing anything. regexr does not have a built-in per-pattern library.Do both tools use the JavaScript regex engine?
Yes. Both voiddo regexlab and regexr.com use the JavaScript (ECMAScript) engine. This means identical support for named capture groups, lookaheads, lookbehinds (ES2018+), the v flag (ES2024), and all standard JS regex behavior. If you need PCRE2 or Python semantics, use regex101 which supports server-side non-JS engines.
Does regexr send my content to a server?
regexr runs regex matching client-side. Only when you save a pattern does it send data (the pattern and test string) to regexr's server to generate a permalink. If you only use it without saving, nothing leaves the browser. voiddo regexlab never sends any data to any server — no save feature, no sync, no analytics on your content.
Is voiddo regexlab free?
Yes — completely free, no account required, no ads, and no rate limits. It is part of the 36 free developer tools at tools.voiddo.com. A Pro plan ($9 lifetime) removes rate limits on heavier tools but regexlab itself has no limits on the free tier.
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