Developer Tools — All 46 Free Online Tools
Every developer tools tool on Toolfyra in one place — 46 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
🗂️ZIP File Extractor
Open and extract ZIP archives free in your browser: see every entry with its size, then download files one by
📦ZIP File Creator
Create a ZIP archive free in your browser: add files, remove any you do not want, and download one tidy compre
🔏File Checksum Verifier
Verify any file's SHA-256, SHA-512, SHA-384 or SHA-1 checksum free in your browser and get an instant MATCH or
📷Webcam Test
Test your webcam in the browser with a live mirrored preview, resolution and FPS readout, one-click snapshot,
🎙️Microphone Test
Test your microphone in the browser: an animated live level meter, a five-second test recording with instant p
⌨️Keyboard Tester
Press keys on your physical keyboard and watch them light up on screen, read key, code and keyCode in a live l
🕵️User Agent Checker
Read your full user-agent string, platform, languages, privacy flags and hardware hints, then copy the whole r
🖥️Screen Resolution Checker
See your screen resolution in CSS and device pixels, available area, devicePixelRatio, color depth and a live
🗝️Passphrase Generator
Build diceware-style passphrases from a local word list with separators, numbers and capitalization. Runs enti
🔒AES Encrypt / Decrypt
Encrypt any text to a portable base64 blob with AES-256-GCM and a PBKDF2 password, or decrypt blobs back — rea
🛡️WebRTC Leak Test
Run a real STUN query to list the IPs WebRTC exposes, compare them with your HTTPS exit IP, and get a plain-En
🟥Dead Pixel Test
Flood your whole screen with pure red, green, blue, white and black to spot dead, stuck and sub-pixel defects