Observed arrival · 2026-10-03
RegexShelf: a regex tester with its limits documented
A browser-based regex tester that highlights matches, displays capture groups, and explains patterns across several regex flavors.
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$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Developers comparing regex behavior across engines
- Worth noticing
- Share links put the pattern, flavor, flags, and test text in the address, despite local execution.
Field notes
Results are presented with UTF-16 offsets and end-exclusive ranges, plus each capture group's value and position; the described table includes groups that did not participate. The worked examples cover named date groups, greedy versus lazy matching, and empty matches, including a Go-specific case where an empty match adjacent to a prior match is omitted. The page also links its flavor notes to engine and language documentation.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue