What you can do here
Developer tools on TeaFun focus on formatting, conversion, and quick inspection. They are for the moments when you need to validate input, reshape config, or inspect a payload without opening a heavier app.
Developer Tools
Developer utilities — converters, builders, and checkers.
10 tools in this category
← HomeWho this category helps
Useful for developers, DevOps, QA, support engineers, and technical writers who need browser-side utilities for JSON, JWT, cron, headers, logs, and config formats.
How to choose the right tool
Start with JSON Formatter for raw payloads, YAML/JSON/TOML Converter for config reshaping, JWT Decoder for token inspection, and HTTP Headers Checker when reviewing responses.
Popular starting points
These starter tools cover the most common browser-side jobs: validating data, inspecting tokens, and checking response details quickly.
ENV / Shell / Docker Converter
Convert .env files to JSON, YAML, TOML, shell export, and Docker ENV instantly in your browser. Nothing is uploaded — all conversion is client-side.
JSON Formatter & Validator
Format, validate, and minify JSON instantly in your browser. Zero network requests — your data never leaves your device.
JWT Decoder
Decode JWT headers and payloads locally in your browser. Inspect claims, expiry, issuer, and timestamps without sending tokens anywhere.
ENV / Shell / Docker Converter
Convert .env files to JSON, YAML, TOML, shell export, and Docker ENV instantly in your browser. Nothing is uploaded — all conversion is client-side.
JSON Formatter & Validator
Format, validate, and minify JSON instantly in your browser. Zero network requests — your data never leaves your device.
JWT Decoder
Decode JWT headers and payloads locally in your browser. Inspect claims, expiry, issuer, and timestamps without sending tokens anywhere.
Base64 Encoder / Decoder
Encode and decode Base64 locally in your browser. Supports text conversion, URL-safe Base64, and file-to-Base64 export.
Cron Expression Builder
Build cron expressions visually for Unix, Quartz, AWS EventBridge, and GitHub Actions. Preview upcoming run times instantly in your browser.
Structured Data Converter
Convert YAML, JSON, and TOML locally in your browser with multi-document YAML support and anchor resolution.
HTTP Security Headers Checker
Paste raw response headers or curl -I output to review common security headers locally, including CSP, HSTS, and COOP.
Log Formatter
Paste JSON, nginx, Docker, syslog, or plain logs to normalize, filter by level, and inspect them locally in your browser.
Reading Time Estimator
Estimate reading and speaking time instantly. Paste any text to get word count, character count, reading time, and speaking time — CJK-aware.
Color Palette + WCAG Checker
Check contrast ratios, AA/AAA compliance, generate palette variants, and export CSS or Tailwind v4 color tokens locally.