Free Developer Tools — JSON, SQL, Regex, Cron, JWT, YAML & More

JSONFix

Format, validate, and AI-fix broken JSON

SQLFormat

Format SQL queries + AI explains what they do

RegexAI

Build regex patterns from plain English

CronAI

Describe schedule in English → get cron expression

ReadMeAI

Generate professional README from any GitHub repo

JWT Decoder

Free

Decode JWT tokens — see header, payload, expiry

YAMLCheck

Free

Validate YAML and convert YAML ↔ JSON

HashGen

Free

Generate SHA-256, SHA-512, Base64, URL-encoded hashes

Base64

Free

Encode and decode Base64 strings

DiffCheck

Free

Compare two texts and see differences highlighted

GitIgnore

Free

Select your stack → get a .gitignore file

ColorPick

Free

Pick colors and get HEX, RGB, HSL, Tailwind formats

SiteSafe

Security

Check security headers and SSL for any website

PingCraft

Monitor

Monitor website uptime with Telegram alerts

ReviewReply

AI-generated professional responses to customer reviews

Why These Tools?

Every developer needs quick utilities — format some JSON, decode a JWT, test a regex, generate a cron expression. Most existing tools are bloated with ads, require signups, or send your data to servers.

These tools are different: they run entirely in your browser (except the AI features), have zero ads, require no signup, and are completely free. The AI-powered tools use Claude for intelligent features like fixing broken JSON, explaining SQL queries, and generating regex patterns from English descriptions.

All tools are open source and hosted on Vercel free tier.

Tool Categories

Formatters & Validators

JSONFix formats and validates JSON with AI auto-fix for broken syntax. SQLFormat beautifies SQL queries with AI explanations. YAMLCheck validates YAML and converts between YAML and JSON formats.

Generators

CronAI converts plain English schedules to cron expressions. RegexAI builds regex patterns from descriptions. ReadMeAI generates professional README files for GitHub repos. GitIgnore creates .gitignore files for any tech stack. HashGen produces SHA-256, SHA-512, and Base64 hashes.

Encoders & Decoders

JWT Decoder shows token claims, expiry, and signature details. Base64 encodes and decodes strings with UTF-8 support.

Security & Monitoring

SiteSafe scans any website for security headers and SSL configuration. PingCraft monitors uptime with Telegram alerts.