Private by design · 28 tools

A polished suite of developer utilities

Free client-side developer tools for JSON, JWT, Regex, Markdown, Cron, QR, CIDR, OpenAPI, HAR, and SQL. Format, validate, generate, and compare locally—no upload. Google sign-in is optional.

Data — Structured content

  • JSON Tools — Format, tree, table, path, schema, TypeScript types, YAML, NDJSON, redact, jump to parse errors.
  • YAML ↔ JSON — Convert, validate, merge, sort keys, multi-doc, jump to errors.
  • XML Tools — Format, minify, validate, XPath, outline, XML ↔ JSON.
  • CSV Tools — CSV/TSV ↔ JSON, Markdown, SQL inserts; sortable preview and column profile.
  • TOML ↔ JSON — Convert TOML and JSON with validation, sort keys, and download.
  • Markdown — Live GFM preview, formatting toolbar, TOC, stats, styled HTML export.
  • HTML Tools — Sandboxed preview, beautify, minify, outline, links, a11y audit, to Markdown.

API — Contracts & traffic

  • OpenAPI Viewer/Diff — Endpoints, details, cURL, lint, breaking-change diff, Markdown docs.
  • Postman Viewer — Browse collections with variables and auth; export cURL, fetch, OpenAPI.
  • cURL Builder — Build or import; export fetch, axios, Python, Go, HTTPie; try it in-browser.
  • HAR Analyzer — Filter, waterfall, timings, per-host stats, sanitized export, cURL.
  • GraphQL Formatter — Format, minify, analyze operations, variables, fetch/cURL snippets.
  • CIDR Calculator — IPv4/IPv6 subnets, scope, binary view, split, contains, range → CIDR.

Security — Tokens & encoding

  • Encoding & Hash — Base64/URL, gzip, SHA, HMAC, HTML entities, data URI.
  • JWT Lab — Decode, sign HS/RS/ES/PS, verify JWK/JWKS, inspect claims.
  • Generators — UUID v4/v7, ULID, passwords and passphrases, API keys, TOTP, fake data.

Compare — Text & config

  • Diff & Compare — Line/word compare, list diff, unified patch, files.
  • Env/Config Diff — .env and JSON diff, secret masking, lint, merge, .env.example.

Dev — Everyday helpers

  • SQL Tools — Format 13 dialects, minify, lint, parameterize, tables and params.
  • Regex Lab — Live highlight, groups, replace, recipes, flags.
  • Base Converters — Text, hex, Base64/32/58, binary, data URI, hex dump, number bases.
  • Time & Timezones — Epoch/ISO, relative time, batch, DST helpers.
  • Cron Lab — Explain 5- or 6-field cron, next runs, timezone-aware schedule.
  • URL Inspector — Parse/build URLs, edit query, encode components.
  • Color Lab — Convert HEX/RGB/HSL/OKLCH, WCAG contrast, scales, harmonies, export.
  • QR Generator — Text, URL, Wi-Fi, vCard, and more; colors, ECC, PNG and SVG.
  • MOV to MP4 — Convert and shrink video to MP4 locally with quality and resolution options.
  • Text Utilities — Text stats, case and line tools, extractors, log redaction, my links.