Free Online Developer Tools
A suite of 283+ hyper-fast utilities — JSON formatter, Base64, hashing, converters, generators & more. 100% private & client-side: every tool runs locally in your browser, so your data never touches a server.
Formatters & Validators
Clean, format, validate, and compare your raw code and text structures.
JSON Formatter
Format, validate, and beautify JSON payloads.
Text Diff / Compare
Side-by-side or unified line/character diff comparison tool.
XML Formatter
Beautify and indent XML strings.
Minifier Suite
Minify HTML, CSS, and JS by stripping comments and whitespace.
Markdown Converter
Convert Markdown to HTML with live preview.
CSS Formatter
Beautify and indent minified or messy CSS.
HTML Formatter
Beautify and indent raw HTML markup.
SQL Formatter
Format SQL queries with keyword casing and indentation.
YAML Formatter
Validate and normalize YAML indentation.
Credit Card Validator
Validate card numbers with the Luhn check and detect the brand.
Email Validator
Check whether an email address is well-formed.
IP Address Validator
Validate and classify IPv4 and IPv6 addresses.
IBAN Validator
Validate an IBAN with the ISO 7064 mod-97 checksum, and see its country and formatted form.
ISBN Validator
Validate ISBN-10 and ISBN-13 book numbers with their checksum digit.
Converters
Transform data between formats — JSON, YAML, CSV, XML, and more.
JSON to YAML
Convert JSON into clean, readable YAML instantly.
YAML to JSON
Convert YAML configuration into valid JSON.
JSON to CSV
Flatten a JSON array of objects into CSV rows.
CSV to JSON
Parse CSV with headers into a JSON array of objects.
JSON to XML
Convert JSON structures into nested XML markup.
JSON Minifier
Strip whitespace to produce compact JSON.
JSON to TypeScript
Generate TypeScript interfaces from a JSON sample.
JSON to SQL
Turn a JSON array of objects into SQL INSERT statements.
CSV to XML
Convert CSV rows into structured XML records.
XML to CSV
Flatten repeated XML records into CSV rows.
INI to JSON
Parse INI config sections and keys into JSON.
JSON to INI
Serialize a JSON object into INI config format.
CSV to Markdown Table
Convert CSV data into a GitHub-style Markdown table.
XML to JSON
Convert XML markup into a structured JSON object.
Number to Words
Spell out numbers in English words.
CSV to SQL
Turn CSV rows into SQL INSERT statements.
Decimal to Binary Converter
Convert decimal (base 10) numbers to binary (base 2).
Binary to Decimal Converter
Convert binary (base 2) numbers to decimal (base 10).
Decimal to Hex Converter
Convert decimal (base 10) numbers to hexadecimal (base 16).
Hex to Decimal Converter
Convert hexadecimal (base 16) numbers to decimal (base 10).
CSV Cleaner
Trim whitespace, drop empty rows, and de-duplicate CSV data.
CSV to HTML Table Converter
Turn CSV data into a ready-to-paste HTML <table>.
Decimal to Octal Converter
Convert decimal (base 10) numbers to octal (base 8).
Octal to Decimal Converter
Convert octal (base 8) numbers to decimal (base 10).
Binary to Hex Converter
Convert binary (base 2) numbers to hexadecimal (base 16).
Hex to Binary Converter
Convert hexadecimal (base 16) numbers to binary (base 2).
CSV to TSV Converter
Convert comma-separated values to tab-separated values.
TSV to CSV Converter
Convert tab-separated values to comma-separated values.
Scientific Notation Converter
Convert numbers between decimal and scientific (E) notation.
JSON to Query String Converter
Turn a flat JSON object into a URL query string.
Query String to JSON Converter
Parse a URL query string into a JSON object.
Octal to Binary Converter
Convert octal (base 8) numbers to binary (base 2).
HTML to JSX Converter
Convert HTML to JSX — class to className, inline styles to objects, and self-closed tags.
JSON to Go Struct
Generate Go structs with JSON tags from a sample JSON object.
SVG to Data URI
Encode an SVG into a URL-encoded or base64 data URI for CSS or img src.
JSON to PHP Array
Convert JSON into a ready-to-paste PHP array using modern short-array syntax.
Seconds to Time Converter
Convert a number of seconds into HH:MM:SS and a human-readable duration.
Centimeters to Inches
Convert centimeters to inches instantly, with a feet-and-inches breakdown and a quick reference table.
Inches to Centimeters
Convert inches to centimeters instantly, with a quick reference table for common values.
Kilograms to Pounds
Convert kilograms to pounds (lb) instantly, with a quick reference table for common weights.
Pounds to Kilograms
Convert pounds (lb) to kilograms instantly, with a quick reference table for common weights.
Binary to Octal Converter
Convert binary (base 2) numbers to octal (base 8).
Hex to Octal Converter
Convert hexadecimal (base 16) numbers to octal (base 8).
Octal to Hex Converter
Convert octal (base 8) numbers to hexadecimal (base 16).
JSON to Rust Struct
Generate Rust structs with serde Serialize / Deserialize derives from a JSON sample.
HTML to Markdown Converter
Convert HTML markup into clean, readable Markdown without a server.
Encoders & Decoders
Safely encode, decode, and convert data formats without leakage.
Base64 Encoder
Encode or decode Base64 strings.
URL Encoder
Safely encode or decode URL parameters.
Base Converter
Convert numbers between binary, octal, decimal, hex, and base 2-36.
ROT13 Encoder / Decoder
Apply the reversible ROT13 letter-substitution cipher.
HTML Entity Encoder / Decoder
Escape or unescape HTML entities like & and <.
Punycode Converter
Convert internationalized domains to and from Punycode.
Text to Morse Code
Translate text into Morse code dots and dashes.
Morse Code to Text
Decode Morse code dots and dashes back into text.
UTF-8 Encoder
Encode text into UTF-8 byte values (hex).
UTF-8 Decoder
Decode UTF-8 byte values (hex) back into text.
Text to ASCII
Convert text into ASCII / Unicode code points.
ASCII to Text
Convert ASCII / Unicode code points back into text.
Base32 Encoder / Decoder
Encode or decode RFC 4648 Base32 strings.
Base58 Encoder / Decoder
Encode or decode Base58 (Bitcoin alphabet) strings.
Roman Numeral Converter
Convert numbers to Roman numerals and back.
Unicode Escape Converter
Escape text to \uXXXX sequences and unescape them back.
Base64URL Encoder / Decoder
Encode or decode URL-safe Base64 (Base64URL).
Backslash Escape Converter
Escape and unescape backslash sequences in strings.
JSON Escape / Unescape
Escape text into a JSON string literal or unescape \n, \t and \uXXXX back to readable text.
Caesar Cipher Encoder / Decoder
Shift letters by any amount to encode or decode a Caesar cipher.
Vigenère Cipher Encoder / Decoder
Encrypt or decrypt text with a keyword using the Vigenère cipher.
Base64 Image Encoder
Convert any image to a Base64 data URI — for CSS backgrounds, HTML src, and email embeds.
Cryptography & Security
Client-side hashing, token decoding, and secure generation.
Password Generator
Generate strong, random passwords locally.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes locally.
JWT Decoder
Decode JSON Web Tokens instantly and offline.
Bcrypt Generator
Generate and verify Bcrypt hashes with custom salt rounds.
MD5 Hash Generator
Generate an MD5 hash from any text.
SHA-1 Hash Generator
Generate a SHA-1 hash from any text.
SHA-256 Hash Generator
Generate a SHA-256 hash from any text.
SHA-512 Hash Generator
Generate a SHA-512 hash from any text.
HMAC Generator
Generate an HMAC signature with a secret key.
CRC32 Checksum Generator
Compute the CRC32 checksum of text.
SHA-384 Hash Generator
Generate a SHA-384 hash from any text.
JWT Encoder
Build and sign HS256 JSON Web Tokens with a secret.
Basic Auth Header Generator
Build an HTTP Basic Authorization header from credentials.
AES Encryption Tool
Encrypt and decrypt text with AES-GCM and a password.
Password Strength Checker
Estimate password strength, entropy, and crack time locally.
PBKDF2 Hash Generator
Derive a PBKDF2 key from a password and salt with SHA-256/384/512 — using the Web Crypto API.
htpasswd Generator
Generate an Apache/nginx .htpasswd line with a bcrypt-hashed password — entirely in your browser.
TOTP Generator
Generate time-based one-time passwords (TOTP / authenticator codes) from a Base32 secret — entirely in your browser.
Generators
Generate identifiers, placeholder data, and assets on demand.
UUID Generator
Generate secure v4 UUIDs.
QR Code Generator
Create customizable QR codes and export as SVG or PNG.
Lorem Ipsum
Generate placeholder paragraphs, sentences, or word lists.
Random Hex Generator
Generate cryptographically random hexadecimal strings.
Random Number String
Generate a random string of digits of any length.
Random String Generator
Generate random strings from a custom character set.
Random Color Generator
Generate random colors as HEX, RGB, and HSL.
MAC Address Generator
Generate random MAC addresses in several formats.
Nano ID Generator
Generate compact, URL-safe Nano IDs.
Credit Card Number Generator
Generate valid test credit card numbers by brand.
ULID Generator
Generate sortable, time-based ULIDs.
Random IP Generator
Generate random IPv4 and IPv6 addresses.
SVG Placeholder Generator
Generate a lightweight SVG placeholder image (any size, colors, and label) as markup or a data URI.
Text Tools
Manipulate, clean, count, and reshape text instantly.
Case Converter
Convert between Sentence, Title, camelCase, snake_case, and more.
Word Counter
Count words, characters, and analyze keyword density.
Text to Binary
Convert text into its 8-bit binary representation.
Binary to Text
Decode 8-bit binary back into readable text.
Text Reverser
Reverse text by characters, words, or lines.
Remove Duplicate Lines
Delete repeated lines and keep your list unique.
Remove Empty Lines
Strip blank and whitespace-only lines from text.
Sort Lines Alphabetically
Sort lines A–Z or Z–A, case-sensitive or not.
Slugify URL Generator
Turn any title into a clean, URL-safe slug.
Find and Replace Text
Find and replace text, with optional regex and flags.
Remove Extra Spaces
Collapse repeated spaces and trim each line.
Remove Accents
Strip diacritics so é becomes e and ü becomes u.
Remove Punctuation
Delete punctuation marks and symbols from text.
Text Repeater
Repeat any text a chosen number of times.
Word Frequency Counter
Count how often each word appears, ranked.
Zalgo Text Generator
Add creepy combining marks to make glitchy Zalgo text.
Upside Down Text Generator
Flip text upside down with mirrored Unicode characters.
Small Text Generator
Make tiny superscript, subscript, and small-caps text.
Strikethrough Text Generator
Cross out text with strikethrough, slash, or underline marks.
Bold Text Generator
Generate Unicode bold and italic text for anywhere.
Wide Text Generator
Create full-width vaporwave aesthetic spaced-out text.
NATO Phonetic Alphabet
Spell text using the NATO phonetic alphabet.
Leetspeak Converter
Translate text into 1337 (leetspeak) and back.
Pig Latin Translator
Translate English text into Pig Latin.
Cursive Text Generator
Create fancy Unicode cursive (script) text.
Bubble Text Generator
Turn text into circled bubble letters.
Add Line Numbers
Prefix every line with a sequential line number.
Remove Line Breaks
Strip line breaks to join text into one block.
Remove HTML Tags
Strip HTML tags to extract plain text.
Extract Email Addresses
Pull every email address out of a block of text.
Extract URLs
Pull every URL or link out of a block of text.
Reverse Word Order
Reverse the order of words in each line of text.
Extract Numbers
Pull every number out of a block of text.
Remove Duplicate Words
Strip repeated words from text, keeping the first of each.
Word Wrap / Text Wrapper
Hard-wrap text to a fixed line width without breaking words.
Shuffle Lines
Randomly reorder the lines of your text.
Reverse List / Line Order
Flip the order of lines so the last becomes the first.
Lines to Comma-Separated List
Join lines into a single comma-separated list.
Comma-Separated to Lines
Split a comma-separated list into one item per line.
Remove Numbers
Strip every digit out of your text.
Text Truncator
Trim text to a set number of characters or words with an ellipsis.
Random Line Picker
Pick one or more random lines from your list.
Markdown to Plain Text
Strip Markdown formatting to get clean, readable plain text.
Tabs to Spaces Converter
Convert tabs to spaces or spaces to tabs with a custom tab width.
Palindrome Checker
Check whether a word, phrase, or sentence reads the same forwards and backwards.
Title Case Converter
Convert text to Title Case, capitalizing each major word while leaving small words like 'a', 'of', and 'the' lowercase.
Remove Line Numbers
Strip leading line numbers from pasted code or text — handles '1.', '1)', '1:' and bare-number styles.
Sponge Case Generator
Convert text to AlTeRnAtInG mOcKiNg CaSe — the classic SpongeBob meme format.
Letter Counter
Count the frequency of each letter in your text.
Anagram Checker
Check whether two words or phrases are anagrams of each other.
Prefix / Suffix Adder
Add a custom prefix and/or suffix to every line of text.
Duplicate Line Counter
Count how many times each line appears — sorted by frequency.
Developer Utilities
Network math, syntax parsers, and everyday developer helpers.
RegExp Tester
Test regular expressions and inspect matches locally.
Subnet Calculator
Compute CIDR subnets, usable hosts, and network ranges.
Cron Parser
Translate cron syntax into plain English.
URL Parser
Break a URL into protocol, host, path, and query parts.
HTML Previewer
Paste HTML and see it rendered live in a safe, sandboxed preview.
HTTP Status Code Reference
Search and look up every HTTP status code and its meaning.
MIME Type Lookup
Find the MIME type for a file extension, or the extensions for a MIME type.
ASCII Table
Full ASCII table with decimal, hex, octal, and binary values for every character.
Chmod Calculator
Build Unix file permissions with checkboxes and read them as octal (755) and symbolic (rwxr-xr-x) notation.
Crontab Generator
Build a cron expression from fields and read it back in plain English.
User Agent Parser
Parse a User-Agent string into browser, operating system, and device — in your browser.
Case Style Converter
Convert identifiers between camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE, and dot.case.
JSON Diff Checker
Compare two JSON objects and see exactly what was added, removed, or changed — a structural diff, not a text diff.
Common Ports Lookup
Search a reference of common TCP/UDP port numbers and the services that use them — HTTP, SSH, DNS, and more.
Markdown Table Generator
Build a Markdown table in an editable grid — add rows and columns, set column alignment — and copy the Markdown.
.gitignore Generator
Generate a .gitignore file by selecting your tech stack.
Web & SEO
Generate meta tags, social cards, and marketing URLs for the web.
Meta Tag Generator
Build SEO title, description, and viewport meta tags.
Open Graph Generator
Generate Open Graph and Twitter Card meta tags.
Robots.txt Generator
Create a robots.txt with allow/disallow rules.
UTM Campaign URL Builder
Append UTM parameters to build trackable campaign URLs.
Hreflang Tag Generator
Generate hreflang link tags for multilingual SEO.
Sitemap XML Generator
Build an XML sitemap from a list of URLs.
SERP Snippet Preview
Preview how your page title and meta description appear in Google search.
Meta Tag Analyzer
Paste a page's HTML head to audit its title, meta, and social tags.
Keyword Density Checker
Count word frequency and keyword density in your content.
JSON-LD Schema Generator
Build structured data (Article, Product, FAQ, Organization) as JSON-LD.
Twitter Card Generator
Generate Twitter/X card meta tags with a live preview.
Open Graph Preview
Preview how a link's Open Graph card looks when shared on social.
Canonical Tag Generator
Generate a rel=canonical link tag to prevent duplicate content.
Twitter / X Character Counter
Count characters against the 280-limit as you draft a post.
Hashtag Generator
Turn keywords or text into ready-to-paste social hashtags.
Reading Time Calculator
Estimate reading and speaking time from your word count.
Readability Score Calculator
Score your text with Flesch Reading Ease and Flesch-Kincaid Grade Level to see how easy it is to read.
htaccess Redirect Generator
Generate Apache .htaccess 301 and 302 redirect rules from a list of old and new URLs.
Design & CSS
Client-side utilities for frontend styling and color.
Color Converter
Convert a color to HEX, RGB, HSL, HSB, and CMYK at once.
HEX to RGB
Convert HEX color codes to RGB / RGBA values.
RGB to HEX
Convert RGB values into HEX color codes.
CSS Box Shadow Generator
Visually design CSS box-shadow with a live preview and code.
CSS Border Radius Generator
Visually craft border-radius with a live preview.
HEX to CMYK
Convert HEX colors to CMYK print values.
CMYK to HEX
Convert CMYK print values to HEX colors.
HEX to HSB
Convert HEX colors to HSB / HSV values.
HSB to HEX
Convert HSB / HSV values to HEX colors.
Color Contrast Checker
Check WCAG contrast ratio between two colors.
RGB to HSL
Convert RGB values to HSL color notation.
HSL to RGB
Convert HSL color values back into RGB.
RGB to CMYK
Convert RGB screen colors to CMYK print values.
CMYK to RGB
Convert CMYK print values into RGB screen colors.
CSS Gradient Generator
Design linear and radial CSS gradients with live preview.
CSS Flexbox Generator
Visually build flexbox layouts and copy the CSS.
CSS Triangle Generator
Generate CSS triangles with the border trick.
CSS Clip Path Generator
Pick a clip-path shape and copy the CSS, with live preview.
CSS Text Shadow Generator
Design CSS text-shadow with a live preview and code.
Color Shades Generator
Generate tints and shades from a base color.
CSS Grid Generator
Build a CSS grid layout visually and copy the generated code.
CSS Filter Generator
Tune blur, brightness, contrast, and more with a live filter preview.
CSS Transition Generator
Build CSS transitions with easing and a live hover preview.
CSS Transform Generator
Translate, rotate, scale, and skew with a live transform preview.
CSS Scrollbar Generator
Style custom scrollbars and copy the cross-browser CSS.
CSS Columns Generator
Create multi-column text layouts with the CSS columns property.
CSS Cursor Tester
Preview every CSS cursor value and copy the one you want.
CSS Outline Generator
Design a CSS outline with style, width, color, and offset.
CSS Blend Mode Generator
Preview mix-blend-mode and background-blend-mode effects.
CSS Named Colors
Browse all 148 CSS named colors with their HEX and RGB values.
CSS Specificity Calculator
Calculate the specificity score of any CSS selector.
PX to REM Converter
Convert px to rem and em (and back) for any root font size.
Glassmorphism CSS Generator
Design frosted-glass cards with backdrop-blur and copy the CSS.
HEX to HSL
Convert a HEX color code to HSL (hue, saturation, lightness) for CSS, with a live preview.
HSL to HEX
Convert an HSL color (hue, saturation, lightness) to a HEX code for CSS, with a live preview.
Neumorphism CSS Generator
Design soft-UI neumorphic shadows and copy the CSS, with a live preview.
CSS Animation Generator
Build CSS @keyframes animations visually — property, duration, easing, and iteration — with a live preview and copy-paste code.
CSS Button Generator
Design a CSS button — colors, padding, radius, border, and hover state — with a live preview and ready-to-copy CSS.
CSS Loader Generator
Generate a pure-CSS loading spinner — size, color, and speed — with a live preview and copy-paste code (no images, no JS).
Color Mixer
Mix two HEX colors at any ratio and get the blended result, plus a gradient of in-between steps.
Color Palette Generator
Generate harmonious color palettes — complementary, analogous, triadic, and more.
RGB to HSB Converter
Convert RGB (red, green, blue) color values to HSB / HSV (hue, saturation, brightness).
HSB to RGB Converter
Convert HSB / HSV (hue, saturation, brightness) color values to RGB.
CSS Variables Generator
Generate a 10-shade CSS custom property scale from any base color.
Font Stack Generator
Browse and copy CSS font-family stacks for system fonts, serifs, monospace, and more.
CSS Unit Converter
Convert between px, rem, em, vw, vh, and pt instantly.
Calculators
Fast, precise calculators for everyday math and dates.
Percentage Calculator
Solve percentage, increase, and change calculations.
Age Calculator
Calculate exact age in years, months, and days.
Unix Timestamp Converter
Convert Unix epoch timestamps to and from human dates.
Tip Calculator
Calculate tip and split the bill between people.
Aspect Ratio Calculator
Solve width or height for a target aspect ratio.
Kilometers to Miles
Convert kilometers into miles instantly.
Miles to Kilometers
Convert miles into kilometers instantly.
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin.
Data Storage Converter
Convert between bytes, KB, MB, GB, TB, and more.
Discount Calculator
Calculate sale price and savings from a discount.
Profit Margin Calculator
Compute profit, margin, and markup from cost and revenue.
BMI Calculator
Calculate Body Mass Index in metric or imperial units.
Loan EMI Calculator
Calculate monthly loan payments, interest, and total cost.
Average (Mean/Median/Mode) Calculator
Compute the mean, median, mode, and range of a number set.
Percentage Change Calculator
Find the percentage increase or decrease between two values.
Compound Interest Calculator
Project savings growth with compound interest and contributions.
Simple Interest Calculator
Calculate simple interest and total from principal and rate.
Time Duration Calculator
Find the duration between two times or dates.
GST / VAT Calculator
Add or remove GST/VAT and see the net, tax, and gross amounts.
Running Pace Calculator
Calculate pace, time, or distance for runs and races.
ROI Calculator
Calculate return on investment as a percentage and net gain.
Break-Even Point Calculator
Find the units and revenue needed to cover your costs.
Speed Converter
Convert between mph, km/h, m/s, knots, and feet per second.
Area Converter
Convert between m², ft², acres, hectares, and more.
Hourly to Salary Calculator
Convert an hourly wage to weekly, monthly, and annual pay.
GCD & LCM Calculator
Find the greatest common divisor and least common multiple of numbers.
Prime Number Checker
Check whether a number is prime and see its factors.
GPA Calculator
Calculate your grade point average on a 4.0 scale from letter grades and credit hours.
Business Days Calculator
Count the working days (Mon–Fri) between two dates, excluding weekends.
PayPal Fee Calculator
Work out PayPal fees and what you actually receive — or what to charge to net a target amount.
BMR Calculator
Estimate your Basal Metabolic Rate and daily calorie needs with the Mifflin-St Jeor formula.
CPM Calculator
Calculate CPM (cost per 1,000 impressions), or solve for cost or impressions.
Mortgage Calculator
Estimate your monthly mortgage payment — principal, interest, property tax, insurance, and PMI — and see the total interest paid.
TDEE Calculator
Calculate your Total Daily Energy Expenditure (maintenance calories) plus goal targets for cutting, maintaining, or bulking.
Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy tape-measurement method, plus lean and fat mass.
Stripe Fee Calculator
Work out Stripe processing fees (2.9% + 30¢) and what you actually receive — or what to charge to net a target amount.
Fibonacci Sequence Generator
Generate any number of Fibonacci terms — including very large ones, using BigInt.
Number Formatter
Format numbers with custom thousand separators, decimal places, and prefix / suffix.