Search tools

Find and open any DevTooKit tool. Use arrow keys to navigate.

Regex Visualizer

Visualize a regex as a Thompson NFA state machine graph. See states, transitions, and epsilon moves. Free online — runs locally, no upload.

Supports: literals, . (any), * / + / ? quantifiers, | alternation, () groups, [a-z] char classes, ^ / $ anchors.

Enter a regex pattern to visualize its NFA state machine

Start state
Accept state (double circle)
Char transition
ε (epsilon — empty)

0

States

0

Transitions

0

Epsilon moves

0

Char moves

Built using Thompson's construction — converts a regex into a nondeterministic finite automaton (NFA). Each circle is a state; arrows show transitions on input characters or epsilon (empty) moves.

About Regex Visualizer

Regex Visualizer is a local-first converters utility on DevTooKit for everyday regex graph tasks. Visualize a regex as a Thompson NFA state machine graph. See states, transitions, and epsilon moves. DevTooKit keeps regex graph work on-device and installable as a PWA for offline use. Pair it with neighboring tools instead of hopping across random websites.

What stays local: Inputs you process with Regex Visualizer.

What you can do with Regex Visualizer

  • Free online regex visualizer — no account required
  • Transform Regex Graph without installing CLI utilities
  • Runs locally in your browser (nothing uploaded for processing)
  • Works offline after installing the DevTooKit PWA

How to use Regex Visualizer

  1. Open Regex Visualizer. Go to the free Regex Visualizer page on DevTooKit.
  2. Enter your input. Paste or type your regex graph data — it stays in this browser tab.
  3. Run the tool. Use Regex Visualizer to get results instantly with no server round-trip for processing.
  4. Copy and continue. Copy the output into your editor, PR, or API client as needed.

Privacy

What stays local: Inputs you process with Regex Visualizer. DevTooKit is local-first — no signup wall, no server-side processing for this tool, and no watermark on results.

Related tools

FAQ — Regex Visualizer

Privacy, offline use, and how this free online tool works.

Does Regex Visualizer upload my data to a server?

No. Regex Visualizer runs in your browser. Your input stays on this device and is not sent to DevTooKit for processing.

Is Regex Visualizer free?

Yes — free, with no account and no paywall to use the core regex graph workflow.

How accurate is Regex Visualizer?

It uses well-known client-side libraries and browser APIs. Unusual edge-case formats may still need a manual check.

Can I use Regex Visualizer offline?

Yes after the first visit. Install DevTooKit as a PWA and this tool keeps working without a network connection.

Browse all 91 DevTooKit tools · More converters