Developer Tools — All 34 Free Online Tools
Every developer tools tool on Toolfyra in one place — 34 free tools that run entirely in your browser. No signup, no uploads, no watermarks: open a tool, use it, close it — your data never leaves your device.
JSON Formatter
Free JSON formatter and validator: beautify messy JSON, minify for production, validate syntax with clear erro
🔍Regex Tester
Free regex tester: test JavaScript regular expressions with live match highlighting and capture groups. Cheat-
🔤Base64 Encoder / Decoder
Free Base64 encoder and decoder with full UTF-8 (Unicode/emoji) support. Encode text to Base64 or decode Base6
🌐URL Encoder / Decoder
Free URL encoder/decoder: percent-encode special characters for safe links, or decode %20-style strings back.
#️⃣Hash Generator (MD5 & SHA)
Free hash generator: create MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes from any text. Everything runs in
🆔UUID Generator
Free UUID v4 generator: create one or bulk-generate hundreds of cryptographically random unique identifiers. C
🎟️JWT Decoder
Free JWT decoder: decode JSON Web Token header and payload, inspect expiry (exp) and issued times. Client-side
⏰Cron Expression Generator
Free cron expression generator: build crontab schedules with presets or custom fields, with plain-English expl
🔢AI Token Counter
Free AI token counter: estimate tokens for ChatGPT, Claude and Gemini, and calculate API costs from editable p
🧪Fake Person Generator
Free fake person generator: create complete fictional test profiles — name, birthday, job, email, username, ph
📧Fake Email Generator
Free fake email generator: create realistic-format placeholder email addresses for testing forms, QA fixtures
✅Credit Card Validator
Free credit card validator: check if a card number is structurally valid (Luhn algorithm), detect the brand, a
📱Phone Number Validator
Free phone number validator: clean, validate and format numbers to E.164 international standard — plus country
📨Email Validator
Free email validator: check address syntax (RFC-style), spot disposable-domain signups, and catch typos like g
💾Data Storage Converter
Free data converter: bytes to KB/MB/GB/TB, bits to bytes, decimal (GB) vs binary (GiB) — exact, instant, offli
🧬HTML Encoder / Decoder
Free HTML encoder/decoder: escape <, >, &, quotes to entities and back — instant, bidirectional, offline.
🧾JSON to CSV Converter
Free JSON→CSV: paste an array of objects, get clean CSV with auto-detected headers; swap to convert back.
🔁CSV to JSON Converter
Free CSV→JSON: paste CSV, get a clean JSON array with headers as keys — RFC quoting handled, all local.
📐XML Formatter / Beautifier
Free XML formatter: indent messy XML for reading, or minify it for transport — instant, local, error-honest.
🗄️SQL Formatter
Free SQL formatter: uppercase keywords, indent joins and conditions — messy queries become readable, all local
📝Markdown Previewer
Free markdown previewer: type markdown, see rendered HTML live — headings, lists, code, links, tables; copy th
🌐IP Subnet Calculator
Free subnet calculator: enter IP/CIDR (e.g. 192.168.1.0/26) — get mask, wildcard, network, broadcast, first/la
🕒Unix Timestamp Converter
Free epoch converter: Unix seconds/milliseconds ⇄ readable date-time in your timezone and UTC — now-button inc
🌈CSS Gradient Generator
Build linear and radial CSS gradients visually: pick colors, angle and stops, watch the live preview, copy the
🌓CSS Box Shadow Generator
Design CSS box-shadows with sliders for offset, blur, spread, color and inset — live preview on a card, copy-r
🚦HTTP Status Code Lookup
Search or browse every HTTP status code (1xx–5xx) with a plain-English meaning and the fix to try. Instant ref
🛰️What Is My IP
See your public IP address (IPv4 and IPv6) instantly and free. One-click copy, no signup, no tracking — the lo
🔎WHOIS Lookup (RDAP)
Look up any domain or IP address free: registrar, registration and expiry dates, status codes and nameservers
🛡️Password Breach Checker
Check if your password appeared in known data breaches — without ever sending it anywhere. Uses the Have I Bee
⚡Internet Speed Test
Test your internet speed free in the browser: download Mbps, upload Mbps and latency — measured against Cloudf
🧪Fake JSON / API Data Generator
Generate realistic fake JSON for tests and demos: users, orders, products with emails, UUIDs, dates, addresses
🔌REST API Tester
Test REST APIs online free: GET/POST/PUT/DELETE with custom headers and JSON body, see status, timing and pret
🌍DNS Lookup
Look up DNS records free: A, AAAA, MX, TXT, NS, CNAME and more via DNS-over-HTTPS. Instant, private, no instal
📑Markdown to HTML Converter
Convert Markdown to clean HTML free with live preview: headings, lists, bold, links, code blocks and quotes. C
📖 Popular guides
- JSON Formatter — how to use
- JSON Formatter — mistakes
- JSON Formatter — faq
- Regex Tester — how to use
- Regex Tester — mistakes
- Regex Tester — faq
- Base64 Encoder / Decoder — how to use
- Base64 Encoder / Decoder — mistakes
- Base64 Encoder / Decoder — faq
- URL Encoder / Decoder — how to use
- URL Encoder / Decoder — mistakes
- URL Encoder / Decoder — faq
- Hash Generator (MD5 & SHA) — how to use
- Hash Generator (MD5 & SHA) — mistakes
- Hash Generator (MD5 & SHA) — faq
- UUID Generator — how to use
- UUID Generator — mistakes
- UUID Generator — faq