Developer tools
Decode, build and debug faster: JWT, cron, encodings and more.
AI Token Counter
Count tokens and estimate cost for GPT-5, Claude 4 and Gemini 3 before you call the API.
Runs in your browser
JSON to TypeScript
Turn any JSON payload into clean, typed TypeScript interfaces in one paste.
Runs in your browser
Linux errno Reference
Search Linux errno values by number, name or message.
Runs in your browser
AI API Compatibility Tester
Paste an OpenAI-format request and see what ports to Anthropic, Gemini, Mistral, Cohere, Groq and Ollama, with the rewritten body for each.
Runs in your browser
AI Cost Calculator
Work out what an AI feature costs per month and per year across the 2026 models, ranked cheapest first.
Runs in your browser
AI Hallucination Risk Estimator
Paste any LLM response and see where it probably made things up, with a 0 to 100 risk score and a checklist of what to verify.
Runs in your browser
AI Prompt Generator
Describe a job once and get back a real brief: role, context, facts, constraints, output shape, variants and review checks.
Runs in your browser
AI Text Cleaner
Strip filler, compare paragraphs and protect key terms, all in your browser.
Runs in your browser
Changelog Generator
Paste raw commits and get sorted release sections, changelog markdown, a SemVer check and a quick QA pass before you publish.
Runs in your browser
Code Comment Generator
Draft the code comments worth keeping: the ones that say why a thing exists, not what the syntax does.
Runs in your browser
CORS Debugger
Pull the real response headers from any URL, see whether a preflight is in play, find the exact thing that's broken, and copy a server config fix.
Cron Expression Generator
Paste a cron expression, expand every field, read it in plain English and preview the real next run times.
Runs in your browser
find Command Generator
Build a Linux find command from dropdowns: path, name, type, size, age and an action, explained live.
Runs in your browser
HTTP Status Code Explainer
Type any HTTP status code to see its family, what it does to browsers and crawlers, and the SEO angle, with a reference table and a live URL check.
Runs in your browser
JSON to CSV and CSV to JSON Converter
Convert JSON to CSV and CSV back to JSON in your browser, with RFC 4180 quoting and type inference.
Runs in your browser
JWT Decoder and Claims Inspector
Decode a JWT, read its claims and weigh the signature risk, all in your browser.
Runs in your browser
Number Base Converter
Convert decimal, hex, binary and octal live in four linked boxes, with a custom base and two's complement.
Runs in your browser
Prompt Improver
Paste a rough AI prompt and get a diagnosis of what is missing, a clearer brief, the changes made and the questions only you can answer.
Runs in your browser
Regex Generator and Tester
Build a practical regex, set the boundaries and flags, then test it against your positive and negative cases. Runs locally in your browser.
Runs in your browser
sed Command Generator
Build a sed command without memorizing the syntax, with line addressing and an in-place flag that warns first.
Runs in your browser
Text Diff Checker
Compare two texts line by line, with ignore case, whitespace and blank line options, plus a unified diff you can copy.
Runs in your browser
Timestamp Converter
Convert any Unix timestamp to UTC, local time and ISO 8601, with batch and timezone views.
Runs in your browser
URL Encoder and Decoder
Decode percent-encoded URLs, parse the query string, flag tracking parameters and pull out nested redirects.
Runs in your browser
UUID Generator
Generate UUID v4 and v7, validate and export, all local.
Runs in your browser
QR Code Generator
Make scannable QR codes for URLs, Wi-Fi, email and text, fully in your browser.
Runs in your browser
Regex Tester
Test a JavaScript regex on real text, with named groups, replace preview and saved patterns.
Runs in your browser
JSON Formatter, Query and Diff
Format, query and diff JSON locally in your browser.
Runs in your browser
Color Converter
HEX, RGB, HSL, HSV and CMYK with a live WCAG contrast check and CSS tokens.
Runs in your browser
Text Case Converter
Convert text between camelCase, snake_case, Title Case and 8 more, with smart camelCase splitting.
Runs in your browser
Base64 Encoder and Decoder
Encode, decode and inspect Base64, Base64URL and data URIs in your browser.
Runs in your browser
Word and Character Counter
Count words, characters, sentences and paragraphs live, with reading time and platform limits.
Runs in your browser
XML Formatter, Parser and Audit
Format, parse and audit XML locally, with checks for sitemaps, feeds, SOAP and SVG.
Runs in your browser
YAML to JSON Converter
Convert YAML to JSON and JSON to YAML in your browser, with clear errors instead of wrong output.
Runs in your browser
YAML Validator and Linter
Validate YAML indentation, duplicate keys and config mistakes in your browser, with a JSON preview.
Runs in your browser
Reading in this category
Anthropic Suspends Claude Fable 5 and Mythos 5
Anthropic disabled Claude Fable 5 and Mythos 5 worldwide after a US government order. The timeline, the trigger, and how to fall back to Opus 4.8 fast.
Build a Local AI Agent with Ollama + Qwen 2.5
How I run a local AI agent with Ollama and Qwen 2.5 in 2026: install on Windows, Linux or macOS, pick the model your VRAM fits, call it from Python and LangChain.
ChatGPT vs Claude vs Gemini 2026
A hands-on ChatGPT vs Claude vs Gemini comparison for 2026, ten real jobs tested through the APIs: code, research, writing, data, vision, cost and latency.
Claude Fable 5 vs Opus 4.8: One Day In
Claude Fable 5 vs Opus 4.8 after a mid-session swap on launch day: 95.0% vs 88.6% SWE-bench, exactly 2x the price, and the safety routing caveat.
curl Cheatsheet: Download Files and Test APIs
A practical curl cheatsheet: download and keep the remote name with curl -O, follow redirects with -L, fetch headers only with -I, and POST JSON with -d.
The find Command Cheatsheet: Recipes You Actually Use
A practical Linux find cheatsheet: find by -name, big files with -size +100M, recent ones with -mtime, delete with -delete, and run -exec on each hit.
Git Rebase vs Merge: A Visual Workflow Guide
Git rebase vs merge, decided in one mental model and five real situations: branch diagrams before and after, the exact commands, and the rule I never break.
The grep Cheatsheet: Search a File, Search a Tree
A practical Linux grep cheatsheet: search one file with grep pattern file, search a whole tree with grep -rn, ignore case with -i, invert with -v, and pick -E or -F.
Cheatsheet Python regex : 20 patterns essentiels
Cheatsheet Python regex : 20 patterns re testés, e-mail, IPv4, IPv6, URL, téléphone, ISO 8601, UUID, découpage CSV, lignes de log, slugs, avec l'edge case de chacun.
Python regex cheatsheet: 20 essential patterns explained
A Python regex cheatsheet of 20 tested re patterns: email, IPv4 and IPv6, URL, phone, ISO 8601, UUID, CSV split, log lines, slugs, with the edge case for each.
Web Workers in 2026: Patterns, Pitfalls and INP
Web Workers in 2026: the patterns I reach for, the ones I skip, transferables, SharedArrayBuffer, Comlink, and how to prove the move actually helped your INP.
Anthropic suspend Claude Fable 5 et Mythos 5
Anthropic a désactivé Claude Fable 5 et Mythos 5 partout après un ordre du gouvernement américain. La chronologie, le déclencheur, et le repli vers Opus 4.8.
Agent IA local avec Ollama + Qwen 2.5
Faire tourner un agent IA local avec Ollama et Qwen 2.5 en 2026 : installer sur Windows, Linux ou macOS, choisir le modèle selon la VRAM, l'appeler depuis Python.
ChatGPT vs Claude vs Gemini en 2026
Comparatif terrain ChatGPT vs Claude vs Gemini en 2026 : dix vrais boulots testés via les API (code, recherche, rédaction, data, vision, coût, latence).
Claude Fable 5 vs Opus 4.8 : un jour avec
Claude Fable 5 vs Opus 4.8 après un changement de modèle en pleine session : 95.0% vs 88.6% sur SWE-bench, exactement 2x le prix, et la réserve du routage sécurité.
L'antisèche curl : télécharger et tester des API
Antisèche curl pratique : télécharger en gardant le nom distant avec curl -O, suivre les redirections avec -L, voir les en-têtes avec -I, faire un POST JSON avec -d.
Antiseche de la commande find : les recettes utiles
Une antisèche find sous Linux : trouver par nom avec -name, les gros fichiers avec -size +100M, les récents avec -mtime, supprimer et lancer -exec sur un résultat.
Git rebase vs merge : guide visuel des workflows
Rebase ou merge avec git, tranché en un modèle mental et cinq situations réelles : branch diagrams avant-après, les commandes exactes, et la règle que je ne casse jamais.
L'antisèche grep : chercher dans un fichier, un arbre
Antisèche grep Linux : chercher dans un fichier, parcourir un arbre avec grep -rn, ignorer la casse avec -i, inverser avec -v, et choisir le moteur -E ou -F.
Web Workers en 2026 : patterns, pièges et INP
Web Workers en 2026 : les patterns que je sors vraiment, ceux que j'évite, transferable, SharedArrayBuffer, Comlink, et comment prouver le gain sur ton INP.