Developer tools

Pretty-print, minify, and validate JSON with the error line called out.

Convert text to Base64 and back, Unicode-safe.

Read the header and payload of a JSON Web Token, with expiry checked.

SHA-1, SHA-256, and SHA-512 digests, computed in your browser.

Percent-encode or decode text and whole URLs, component by component.

Test a pattern against sample text with live match highlighting and groups.

Read a crontab line in plain English and see its next run times.

Convert between Unix time and human dates, in your zone and UTC.

Translate a color between HEX, RGB, and HSL with a live swatch.

Turn a JSON array into CSV, or a CSV table back into JSON.

Compare two blocks of text and see exactly what changed, line by line.

Minify HTML, CSS, or JavaScript code to save file size.

Format and beautify SQL queries with proper indentation.

Convert configuration files between JSON and YAML formats.

Encode or decode HTML entities to prevent rendering issues.

Escape or unescape string special characters and slashes.

Calculate octal and symbolic notations for Linux file permissions.

Parse and analyze browser, OS, and device info from a User-Agent string.

Design beautiful CSS linear and radial gradients visually.

Design outer and inset CSS box shadows visually with preview.

Design rounded borders visually for CSS custom boxes.

Convert raw SVG code into a CSS-ready percent-encoded Data URI.

Analyze color contrast ratios against WCAG 2.0 AA/AAA accessibility standards.

Extract host, path, port, protocol, and query parameters from any URL.

Query A, AAAA, MX, NS, TXT, and CNAME records using Cloudflare DoH.

Calculate subnets, hosts, ranges, broadcast, and CIDR prefix masks.

Generate cron schedules visually and translate to crontab lines.

Generate visual CSS polygon clip paths for shapes and layouts.

Generate smooth organic liquid CSS blob shapes.

Generate smooth SVG wave divider shapes for sections.

Searchable git commands quick reference guide.

Searchable regex syntax reference guide.

Searchable reference of all official HTTP status codes.

Searchable list of file extensions and MIME content types.

General operating systems and development editor shortcuts guide.

Record your screen and system/microphone audio directly in-browser.

Record audio from your microphone natively in-browser.

Generate secure Bcrypt hashes or verify passwords against hash codes.

Calculate secure keyed-hash message authentication codes (HMAC).

Encrypt and decrypt text payload with secure AES-GCM password keys.

Generate secure 2048-bit RSA Public/Private keys in PEM format.

Generate 2FA validation codes from base32 seed keys.

Generate cryptographically secure tokens, hex codes, or UUIDs.

Test password entropy, length, complexity, and get strength advice.

Generate secure BIP39 compliant 12 or 24-word passphrases.

Find geolocation metadata for any IP address.

Check server response headers and status codes in-browser.

Trace redirect loops and URL paths dynamically.

Calculate webpage source code weight in kilobytes.

Simulate a crawler bot extracting plaintext page weights.

Extract Facebook OG and Twitter meta card tags from any page.

Simulate custom mobile viewport rendering for layout testing.

Detect your public IPv4 and IPv6 addresses side-by-side in real-time.

Detect private local IP addresses leaking through WebRTC connections.

Learn how to test and verify if your DNS queries leak outside your VPN.

Check Canvas, WebGL, AudioContext, and system font footprint uniqueness.

Test your download connection transfer speed client-side.

Check round-trip ping latency to AWS, Cloudflare, and Google servers.

Inspect HTTP request headers and client environment variables.

Verify if your IP address is blacklisted on major anti-spam databases.

Trace SMTP hops and check SPF/DKIM flags from raw email headers.

Inspect a domain's DNS MX mail servers and SPF safety validation records.

Track screen resolution, viewport bounds, and pixel ratios in real-time.

Simplify resolution dimensions into mathematical aspect ratios (e.g. 16:9).

Calculate display pixel density (PPI) based on size and resolution.

Extract emails, URLs, IPs, and card numbers from raw unstructured text.

Encrypt and decrypt text payload using simple bitwise XOR calculations.

Validate and format raw XML markup structures with indentation.

Format and indent TOML configuration syntax parameters.

Escape command line arguments for Bash, Windows CMD, and PowerShell.

Encode text to and decode from Base32 (RFC 4648) format.

Generate HTTP Basic Authentication headers from username and password.

Browse, filter, and inspect CSV files inside an interactive spreadsheet table grid.

View diagnostic information about your browser, OS, screen resolution, and hardware.

Convert docker run commands into clean docker-compose YAML configuration files.

Encode strings to hexadecimal representation and decode hex back to text.

Upload any file to view its raw binary bytes in a classic hex dump layout.

Convert IPv4 addresses between dot-decimal, binary, octal, hexadecimal, and integer formats.

Expand a CIDR block or IP range into a complete list of individual IP addresses.

Calculate subnets, network details, usable IP range, and masks from CIDR notation.

Generate RFC 4193 Unique Local IPv6 Address (ULA) prefixes.

Compare two JSON objects side-by-side and highlight additions, edits, and deletions.

Query and extract elements from JSON data using standard JSONPath queries.

Press any key to view its Javascript KeyboardEvent key, code, and keycode values.

Generate random, formatted Media Access Control (MAC) addresses.

Generate random, non-conflicting port numbers for dev, databases, or web servers.

Open, browse, and execute SQL queries on SQLite `.db` database files in-browser.

Reveal target URLs from Outlook Safelinks, Proofpoint, and other tracking redirects.

Generate Crockford Base32 lexicographically sortable unique IDs and decode timestamps.

Connect, listen, and send test messages to WebSocket endpoints securely.

Convert JSON documents to structured XML markup tags.

Diagnose individual keyboard keys on an interactive visual keyboard layout.

sign/create tokens

generate types from JSON

generate structs from JSON

convert a cURL command to fetch/axios/Python

Apache password file entries

time-ordered UUIDs

build tables visually

unified diff and patch preview

guess hash type from a digest

domain registration details

inspect a site's TLS cert

decode an uploaded QR image

configurable dice

random coin toss

ZIP Creator *(TinyWow, 11zon)* online tool

ZIP / RAR / 7z Extractor *(11zon, FreeConvert.in)* online tool

TOML ↔ JSON / YAML Converter *(Luminus formats TOML but can't convert it)* online tool

vendor/OUI database

canonicalize gmail dots/aliases

compare benchmark run means/variance

completion time from rate and quantity

rich text → HTML

payment QR with UPI ID and amount

Standard Deviation / Variance Calculator (population & sample) online tool

Dice Probability / Coin Flip Probability / Lottery Odds *(pairs with the Dice Roller + Coin Flip already in Part 2)* online tool

Carbon Footprint Calculator (general + flight, meat, plastic, crypto, AI water footprint) online tool

Lat/Long Distance Calculator + Antipode & Azimuth Calculators online tool

password entropy, Hamming code & distance, parity bit, logic gate, floating-point (IEEE-754) inspector, RAID capacity, RAM latency, duty cycle, ASCII/

bandwidth, download time, upload time, data transfer, streaming bitrate, uptime (SLA nines), baud rate, bandwidth-delay product

CBM, dimensional weight, freight class, pallet, container loading, reorder point, takt time, DPMO

wind chill, earthquake magnitude, rainfall, rain-to-snow, sunrise/sunset, sunbathing/UV

Christmas countdown, Easter date, Diwali/festival countdown, Mayan calendar

Vigenère Cipher *(closes the one gap flagged in Part 2)* online tool

Hash Identifier, Caesar Cipher Shifter *(both already listed in Part 2)* online tool

PERT Calculator, Age on Other Planets, Day-of-Week Calculator online tool

Popup Blocker Test online tool

CORS Test online tool

CSP (Content Security Policy) Test online tool

Service Worker Support Test online tool

Eval / JavaScript Execution Test online tool

Dark Mode Detection Test *(`prefers-color-scheme`)* online tool

Ad/Tracker Blocking Rules Test online tool

expand shortened & redirect chains

aggregate score across all of the above

this tests the , not the image)*

Canvas Fingerprint Detector online tool

ClientRects Fingerprint Detector online tool

Font Fingerprint Detector *(enumerate installed fonts)* online tool

WebGL Fingerprint / GPU Report online tool

WebGPU Fingerprint / Capability Report online tool

AES on arbitrary files, client-side

MD5/SHA-1/SHA-256 of a dropped file, with expected-hash comparison

split a large file into parts and rejoin

WebRTC direct browser-to-browser send

read file metadata

inspect/beautify a page's loaded scripts

ePub Reader online tool

MOBI Reader online tool

LaTeX Editor + live preview *(fits alongside `markdown-editor`)* online tool

classic mini-games

Magic Squares / Sudoku Solver & Generator online tool

Reaction Time Test (\"Hit the Dot\") *(also an Omni tool)* online tool

dual-listed in Part 5)*

preview and inspect a local font file

full CRUD, not just viewing

the inverse of `html-css-js-minifier`

confirmed by a second source)*

QR Code Reader *(already in Part 2)* online tool