Free · Native JS RegExp · Live highlighting

Regex you can actually watch in action.

Pattern + flags + test string — real-time match highlighting with colored capture groups and a curated preset sidebar for common patterns.

Pattern

//

Test string

2 matches

Users created today:
- alice@lokall.app (id: f47ac10b-58cc-4372-a567-0e02b2c3d479)
- bob+newsletter@example.com (id: 550e8400-e29b-41d4-a716-446655440000)
Shipped at 2026-05-10T09:00:00Z from 192.168.1.42.
Check https://lokall.app/tools for more.
  • [23..39] alice@lokall.app
  • [85..111] bob+newsletter@example.com

Common patterns

— How it works

Four steps

  1. 1

    Paste your pattern

    Any JavaScript RegExp. The slashes are visual only; enter just the body.

  2. 2

    Pick flags

    g / i / m / s / u / y — toggle individually or type freeform.

  3. 3

    Edit the test string

    Matches highlight live in different colors; capture groups show their indexed values.

  4. 4

    Grab a preset

    Email, URL, UUID, IPv4, ISO date, phone, hex color, slug — one click to apply.

— Questions

Frequently asked

Is this the same flavor as regex101?+

It's native JavaScript RegExp — the same engine your browser runs. For Python/PCRE differences you'd need a different tool; here everything is JS.

What flags do I need?+

g for global (find all matches), i for case-insensitive, m for multiline ^/$, s for dot-matches-newline, u for Unicode, y for sticky. Most patterns need g + i.

Why does the highlighter sometimes only show one match?+

Without the g flag, a regex only finds the first match. Toggle g to highlight every occurrence.

Can I save patterns?+

The common-pattern sidebar is curated; personal pattern storage would need an account. Paste your own into the pattern field and copy the /…/flags back out when done.

— More free tools

Keep building

JSON formatter

Pretty-print, minify, sort keys, validate — plus one-click TypeScript type inference.

SVG optimizer

Paste or drop an SVG to strip metadata, minify paths, and optionally convert to React JSX.

— Shipping to the App Store?

Translating screenshots into every locale is what lokal was built for. Upload once, ship to every store.

Explore lokal