Regex-LE

Name: Regex-LE
Author: nolindnaidoo

Find, test, and validate the regular expressions in any file — match reports and built-in ReDoS screening.

FreeOpen sourceMITNo network access

Install for VS Code Source on GitHub

Regex-LE in use: Find, test, and validate the regular expressions in any file — match reports and built-in ReDoS screening.

What Regex-LE does

A regular expression is easy to write and hard to trust. Regex-LE finds every pattern in the current file, runs one against the document to show real matches with line and column positions and capture groups, and screens each pattern for the shapes that cause catastrophic backtracking. Three commands: extract, test, validate.

What people use it for

List every regex pattern found in the document, literals and RegExp constructors alike.

Run a found — or manually entered — pattern against the file and see matches with positions and named capture groups.

Check every pattern for syntax errors and screen it for ReDoS-prone shapes before it reaches production.

Install Regex-LE

VS Code

ext install nolindnaidoo.regex-le

Open Quick Open (Cmd/Ctrl+P) and paste.

Cursor / VSCodium

cursor --install-extension OffensiveEdge.regex-le

VS Code forks pull from Open VSX, where the namespace is OffensiveEdge.

ZedComing soon

npx -y regex-le-mcp

Works in Zed today — add the command above as a custom MCP server from the agent panel, and extract_patterns appears in its tool list. The one-click listing in Zed's extension registry is a pull request awaiting review. Track the review.

AI agents

npx -y regex-le-mcp

Runs Regex-LE's engine as an MCP server, so an agent can call extract_patterns with no editor involved. VS Code 1.101+ needs nothing — the extension registers it for you.