letools

Find every regex in a codebase, and report which can be driven into catastrophic backtracking

Lint Jev and Luna questions: a VS Code extension, a command line for CI and an MCP server, for TypeSafe's Jev and OpenAI's Decisions API

Find the Unicode that hides meaning — bidi controls, invisibles, homoglyphs, mixed scripts

Compare the dotenv files in a tree, and say which keys are missing from which

Extract every quantity with its unit, normalized, and refuse the ambiguous ones by name

Extract every URL in a codebase, with its protocol and exact position

Extract every date and timestamp, and the exact instant each one resolves to

Find hardcoded credentials in a codebase, and never print one into the report

Extract every IP address, CIDR block and MAC, normalized and classified by scope

Extract every string in a codebase, with its position, so a person can read them

Extract every file path in a codebase, and say whether it still points at anything

Check whether a page is scrapeable before the scraper is written, and say when it cannot tell

Extract every hardcoded number in a codebase, so a person can check them

Extract every UUID, ULID, NanoID, ObjectId and Snowflake, and decode the time inside

Find where one dependency is constrained differently across a repository's manifests

letools.dev — the hub site for the LE family of VS Code extensions, by nolindnaidoo. Static Next.js + HeroUI on Vercel.

Identify the i18n library a project uses, then audit its catalogs by that library's rules

Extract every color in a codebase, and say which ones are not in your palette

Scrapeability Checker for Smart Web Scraping 2026