Open source

Tools I built, free for everyone.

Small utilities that started as solutions to my own day-to-day problems, then became tools for the community. Several offer features that other apps charge for.

Free
Open source
No ads
No personal data collected

Learning

Pathfinder AI

Find your path into AI

An AI career roadmap you walk instead of read. Explore a 3D world of floating islands, collect 377 skill gems, play a challenge on each island, and follow the AI Developer, AI Engineer or AI Forward Deployed Engineer path to the summit.

Three career paths: AI Developer, Engineer and Forward Deployed Engineer
377 skill gems with plain-English explanations
Printable roadmap and a Skill Passport with a completion certificate

Next.jsTypeScriptThree.jsReact Three FiberZustand

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AI utility

Token Counter

Exact where it can be, honest where it can't

Paste text, pick a model, and see the token count, every token boundary and the token IDs. Each count is labelled exact, proxy or estimate, so you always know how far to trust it. Runs entirely in your browser — no API key needed.

OpenAI, Anthropic, Google, Meta, Mistral, Qwen, DeepSeek and more
Per-count trust label instead of a single unqualified number
Tokenizers run locally and are cached after first use

Next.jsTypeScriptTailwind CSSHugging Face tokenizers

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Documents

PDFKit

Every PDF tool you need, on one page

A self-hosted, iLovePDF-style app with 12 PDF tools — merge, split, compress, OCR, convert to Word or Markdown, protect and unlock. Five tools run entirely in your browser, and nothing is stored.

OCR in 14 languages, up to three combined per document
Compress with font subsetting and content-stream rewriting
No accounts and no stored files

Next.jsFastAPIGhostscriptqpdfTesseract

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Documents

Markdown2PDF

Markdown to PDF and HTML, on your device

A privacy-first Markdown converter with live preview. Handles GitHub Flavored Markdown, LaTeX math and Mermaid diagrams, and exports vector PDFs or a single self-contained HTML file. Your document never leaves the browser.

LaTeX math, Mermaid diagrams and eight syntax-highlight themes
Page size, margins, headers and page numbers for PDF export
Zero requests carry your document — check the Network tab

Next.jsTypeScriptCodeMirrorPaged.jsMermaid

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Developer

DiffLab

Compare anything, miss nothing

A diff and comparison tool for text, code, JSON, spreadsheets, images and documents, modelled on Diffchecker. Compare side by side in your browser and share a result only when you choose to.

Five modes: text, JSON, spreadsheet, image and PDF/DOCX
Semantic JSON diff that ignores key order and formatting
Share via a compressed link or a short link with expiry

Next.jsTypeScriptCodeMirrorPrismaPostgreSQL

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Developer

Keyforge

Keys that never leave your browser

Generate UUIDs, GUIDs, strong passwords and API keys locally with the Web Crypto API. Bulk-generate up to 100 values, see live entropy, and export to CSV or JSON. Nothing is sent to a server.

UUID v4 and v7, Microsoft-style GUIDs, passwords and API keys
Live entropy and strength meter
Unbiased selection via crypto.getRandomValues

Next.jsTypeScriptWeb Crypto APITailwind CSS

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Network

NetGauge

Speed, latency and bufferbloat in one test

An internet speed test that goes beyond a single number: download, upload, latency, jitter and loaded latency, graded for bufferbloat and rated for gaming, video calls and large uploads.

Bufferbloat grade from A+ to F
Per-use-case verdicts instead of raw numbers
Shareable results, CSV/JSON export, installable PWA

Next.jsTypeScriptCloudflare WorkersPrismaRecharts

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