Online Regex Tester Alternatives
Comparing ToolCrux, regex101, Regexr, and Rubular — flags, match groups, explanation pane, engine support, and embeddability.
Feature Comparison
| Feature | ToolCrux | regex101 | Regexr | Rubular |
|---|---|---|---|---|
| Live match highlighting | ✓ | ✓ | ✓ | ✓ |
| Match groups display | ✓ | ✓ | ✓ | ✓ |
| Named capture groups | ✓ | ✓ | ✓ | ✗ Ruby only |
| Regex explanation pane | ✗ | ✓ (best) | ✓ | ✗ |
| Engine support | JS only | JS / Python / PHP / Go / Java | JS only | Ruby only |
| Replace / substitution mode | ✓ | ✓ | ✓ | ✗ |
| Shareable URL | ✓ | ✓ | ✓ | ✓ |
| Embeddable via iframe | ✓ | ✗ | ✗ | ✗ |
| Chain output to another tool | ✓ | ✗ | ✗ | ✗ |
| Dark mode | ✓ | ✓ | ✓ | ✗ |
| Account / save patterns | ✗ | ✓ | ✓ | ✗ |
regex101 wins for multi-engine support and explanation panes — use it when you need Python, PHP, or Java regex with token-by-token explanation. ToolCrux is the right pick for JavaScript regex, embedding a live tester in docs, or chaining matched output to another tool. Regexr is a solid middle ground. Rubular is Ruby-only.
Where ToolCrux Wins
Embedding in documentation. ToolCrux is the only regex tester in this comparison that can be embedded via iframe. Authors writing regex tutorials can drop a live tester pre-filled with the example pattern directly into a page. regex101 and Regexr do not support embedding.
Workflow chaining. When extracting a field from a log line with a regex, you often want to do something with the matched text. ToolCrux lets you pass matched output directly to the next tool without copy-pasting.
Where regex101 Wins
regex101’s explanation pane is genuinely outstanding — it parses your regex and explains every token in plain language. It also supports Python, PHP (PCRE), Go, and Java engines, so you can test against the exact runtime. If you write regex in those languages, regex101 is the better tool. ToolCrux currently supports JavaScript regex only.
When to Use Each Tool
| Use case | Best pick |
|---|---|
| JavaScript regex testing | ToolCrux |
| Python / PHP / Go / Java regex | regex101 |
| Understand what each token does | regex101 (explanation pane) |
| Embed a live tester in docs | ToolCrux (iframe embed) |
| Chain matched text to another tool | ToolCrux (chaining) |
| Ruby regex | Rubular |
Frequently Asked Questions
What is the best online regex tester?
regex101 is the most feature-rich for multi-engine support and explanation panes. ToolCrux is the best for JavaScript regex, embedding in docs, or chaining matched output to another tool.
Does ToolCrux support named capture groups?
Yes. ToolCrux supports all modern JavaScript regex including named capture groups (?<name>...), lookaheads, lookbehinds, and the d flag for match indices.
Can I embed a regex tester in my documentation?
Yes. ToolCrux Regex Tester is available as an embeddable iframe via /embed/regex-tester. Use the ?data= parameter to pre-fill a pattern and test string.
Does ToolCrux support Python or PHP regex?
No. ToolCrux supports JavaScript regex only. For Python, PHP, Go, or Java testing with an explanation pane, use regex101.
Can I save and share a regex pattern from ToolCrux?
Yes. ToolCrux generates a shareable URL with your pattern and test string encoded so colleagues can open it pre-filled.