Tools That Work Offline

Pretty-print and beautify JSON with custom indentation.

Validate JSON syntax and see detailed error diagnostics.

Compress JSON by removing whitespace and show bytes saved.

Diff two JSON documents and list added, removed, and changed paths.

Explore JSON as a collapsible, color-coded tree.

Convert JSON into well-formed, indented XML.

Convert JSON documents to clean, readable YAML.

Flatten a JSON array of objects into a CSV spreadsheet.

Escape special characters for use inside a JSON string.

Reverse JSON string escaping back to readable text.

Explore JSON paths and evaluate simple JSONPath queries.

Infer a JSON Schema from a sample JSON document.

Count words, characters, sentences, and reading time.

Count characters and bytes with limit presets.

Convert text between 11 different letter cases.

Turn any text into a clean, URL-friendly slug.

Deduplicate lines of text with flexible matching.

Sort lines alphabetically, numerically, or by length.

Reverse text by character, word, line, or sentence.

Search and replace text with plain or regex matching.

Generate placeholder text for mockups and designs.

Compare two texts line-by-line with an LCS diff.

Analyze readability with Flesch score and syllable stats.

Add or remove line numbers from text with custom formatting.

Repeat text a set number of times with custom separators.

Trim, collapse, and clean up whitespace in text.

Shuffle a list of lines and optionally pick a random subset.

Split delimited text into aligned columns and re-join it.

Turn text into a big ASCII banner using letters and numbers.

Prettify and align Markdown tables with column alignment.

Detect non-ASCII, invisible, smart-quote, and emoji characters.

Generate acronyms, initials, or camelCase from phrases.

Spell out text using the NATO phonetic alphabet.

Obfuscate text with ROT13, zero-width spaces, or leetspeak.

Align delimited text into padded, readable columns.

Generate lorem ipsum text wrapped in HTML tags.

Generate random strings from a custom pattern.

Beautify and indent messy HTML markup.

Beautify or minify CSS with safe string handling.

Design linear, radial, and conic gradients visually.

Layer multiple box-shadows with a live preview.

Visually build flexbox layouts and copy the CSS.

Design CSS grid layouts with live preview.

Fine-tune per-corner border radii visually.

Create frosted-glass UI effects with live preview.

Generate parametric SVG wave shapes for sections.

Generate a complete SEO and social meta tag block.

Build keyframe animations visually with a live preview.

Layer multiple text-shadows with a live preview.

Generate arrow and triangle shapes with borders or clip-path.

Design polygon clip-path shapes with a live preview.

Translate common Tailwind utility classes into plain CSS.

Build an editable HTML table and export HTML + CSS.

Convert between px, rem, em, %, pt, vw, and vh.

Searchable reference of common HTML character entities.

Tune blur, brightness, contrast, and more with a live preview.

Design custom scrollbars with live preview.

Simplify ratios and compute matching dimensions.

Build a custom property theme with a live preview.

Combine translate, rotate, scale, and skew with a live preview.

Create soft UI neumorphic shadows with a live preview.

Shrink JPEG, PNG, and WebP images without a server.

Resize images to exact pixel dimensions with locked aspect ratio.

Convert images between PNG, JPEG, and WebP in your browser.

Crop images by dragging a selection box, right in your browser.

Generate downloadable QR codes for any text or URL.

Generate a full set of favicon sizes from one image.

Strip comments, metadata, and whitespace from SVG markup.

Convert images to Base64 data URLs and back again.

Sample any pixel color from an uploaded image.

Inspect an image's dimensions, size, type, and aspect ratio.

Convert any image into ASCII text art in your browser.

Add a custom text watermark to your images.

Extract the dominant colors from any image.

Slice a sprite sheet into individual frame images.

Preview how your page appears in Google search results.

Generate Open Graph and Twitter Card meta tags.

Build JSON-LD structured data for common schema types.

Create a robots.txt file with custom crawl rules.

Generate an XML sitemap from a list of URLs.

Generate canonical link tags to avoid duplicate content issues.

Analyze keyword frequency and density in your text.

Build JSON-LD FAQPage structured data from Q&A pairs.

Generate JSON-LD BreadcrumbList structured data.

Analyze HTML for missing or problematic meta tags.

Convert between CSV and JSON with delimiter and header options.

Convert YAML to JSON and JSON to YAML.

Convert XML to JSON and JSON to XML using the browser's DOMParser.

Convert Markdown to HTML with a live preview.

Convert numbers between binary, octal, decimal, hex, and custom bases.

Convert length, weight, temperature, area, volume, speed, and data-size units.

Convert CSV into a Markdown or HTML table with alignment options.

Parse simple SQL INSERT INTO statements into JSON rows.

Convert text to binary or octal codes and back.

Convert between numbers and Roman numerals.

Infer TypeScript interfaces or type aliases from JSON data.

Generate SQL INSERT statements from a JSON array of objects.

Convert CSV data into well-formed XML with custom tag names.

Convert TOML configuration files to JSON and back.

Convert between milliseconds, seconds, minutes, hours, days, and weeks.

Convert bytes, KB/MB/GB/TB with binary (KiB/MiB) or decimal units.

Convert between base64/data URI text and image previews.

Convert numbers into English words, with a currency mode.

Generate Go structs with JSON tags from JSON data.

Generate Python dataclasses from JSON data.

Convert HTML markup into clean Markdown syntax.

Generate SQL INSERT statements from CSV data.

Convert between spreadsheet column numbers and letters.

Encode or decode text to/from Base64, UTF-8 safe.

Encode or decode strings using encodeURIComponent/encodeURI.

Encode or decode HTML entities in text.

Generate SHA-1/256/384/512 hashes of text.

Sign a message with HMAC using a secret key.

Decode a JWT's header and payload, and check expiry.

Encrypt or decrypt text with AES-GCM and a passphrase.

Generate cryptographically secure random strings.

Encode or decode text with ROT13 or any Caesar shift.

Hash text or a file and compare against an expected checksum.

Generate RSA or ECDSA key pairs and export them as PEM.

Compute SHA-1/256/384/512 digests of a local file.

Encode or decode text with the classic Vigenère cipher.

Encode or decode text using RFC 4648 Base32.

Generate bulk RFC 4122 v4 UUIDs with formatting options.

Generate sortable ULIDs with timestamp and random components.

Create secure passwords with custom length and character sets.

Generate arrays of mock JSON records from a simple field schema.

Generate random fake user records with names, emails, and addresses.

Generate inline SVG placeholder images with custom size and colors.

Build a .gitignore file from built-in language and OS presets.

Generate random integers, decimals, dice rolls, and shuffled lists.

Generate Luhn-valid fake card numbers for testing.

Pick random emoji or symbols from curated categories.

Convert between Unix timestamps and human-readable dates.

Format a date using custom patterns and Intl presets.

Convert a datetime across multiple IANA timezones at once.

Calculate the difference between two dates, or add/subtract time.

Calculate exact age and countdown to the next birthday.

Explain a 5-field cron expression and list upcoming run times.

Convert dates and durations to and from ISO 8601 format.

Find the ISO week number, day of year, and quarter for any date.

Count business days between two dates, excluding holidays.

Live countdown to any date and time.

Check if a year is a leap year and find nearby leap years.

Total up work hours across shifts with breaks and hourly pay.

Convert a date to its day-of-year number, or back again.

Convert a list of Unix timestamps to readable dates in bulk.

Convert colors between HEX, RGB, HSL, HWB, OKLCH and CMYK.

Check WCAG 2.1 contrast ratio between two colors.

Generate complementary, analogous, triadic and other palettes.

Generate a 50–950 tint and shade scale from one color.

Simulate how a palette looks with common color vision deficiencies.

Blend two colors with a ratio slider and preview CSS blend modes.

Extract and normalize colors from CSS gradients or lists.

Generate random colors and palettes with HSL constraints.

Calculate network, broadcast, host range, and mask from an IPv4 CIDR.

Expand a CIDR block into individual addresses, or compress a range into CIDR blocks.

Convert IPv4 to decimal/hex/binary, and expand or compress IPv6.

Break a URL into protocol, host, port, path, query, and hash.

Convert between URL query strings and JSON, with nested bracket support.

Parse a user-agent string into browser, engine, OS, and device type.

Searchable reference of HTTP status codes with meaning and usage guidance.

Validate and reformat MAC addresses, and look up the OUI vendor prefix.

Search well-known TCP/UDP ports and their services.

Look up common HTTP headers and explain pasted raw headers.

Searchable reference of DNS record types with examples.

Expand an IPv6 address to full form or compress it to shorthand.

Search file extensions and their MIME types.

Calculate X% of Y, percent change, and reverse percentages.

Compute mean, median, mode, variance, and more from a list of numbers.

Solve, simplify, and scale ratios and aspect ratios.

Add, subtract, multiply, divide, and simplify fractions.

Check primality, factorize numbers, list primes, and compute GCD/LCM.

Convert between decimal, scientific, and engineering notation.

Add, multiply, transpose, and invert matrices with an editable grid.

Round, floor, ceil, or truncate a list of numbers to decimals or multiples.

Solve ax² + bx + c = 0 with real or complex roots.

Find the greatest common divisor and least common multiple of numbers.

Project investment growth with compounding and recurring contributions.

Compute logarithms of any base and exponentiation results.

Generate arithmetic, geometric, or Fibonacci-like number sequences.

Test regular expressions with live match highlighting.

Build cron expressions visually with a human-readable description.

Convert .env files to JSON, YAML, or shell exports.

Escape and unescape strings for JSON, JS, HTML, XML, SQL, RegExp, and shell.

Convert identifiers between camelCase, snake_case, kebab-case, and more.

Conservatively strip comments and whitespace from JS or CSS.

Build a request and generate curl, fetch, axios, and more.

Validate and inspect UUIDs, including version and timestamp.

Convert a curl command into JavaScript fetch() code.

Convert a JS object literal into strict, valid JSON.

Searchable reference of common git commands with copy buttons.

Lint a Dockerfile for common best-practice issues.

Validate package.json fields, semver ranges, and scripts.

Compare versions and test semver ranges (^, ~, >=).

Side-by-side line diff of two code snippets with stats.

Sort, dedupe, and filter lines with regex include/exclude.

Searchable regex syntax reference with examples and copy buttons.

Unix permission calculator: checkboxes, octal, and symbolic.

Format and indent SQL queries for readability.

Validate YAML and preview it as JSON.

Generate Apache .htaccess redirect and rewrite rules.

Format and indent GraphQL queries and mutations.

Remove comments from JS, HTML, Python, or SQL source.

Convert indentation between tabs and spaces.

Inspect a PDF's title, author, version, page count and encryption.

Pull readable text out of uncompressed PDF content streams.

Render Markdown into a printable page and save it as a PDF.

Turn pasted HTML into a print-ready page you can save as PDF.

Turn CSV data into a paginated, printable table for PDF export.

Get word, character and paragraph counts for text-based documents.

Estimate password entropy, crack time, and get actionable advice.

Build a Content-Security-Policy header from per-directive sources.

Grade HTTP response headers against security best practices.

Decode a JWT and audit its claims for common issues.

Generate .htpasswd lines using SHA-1 or plain text.

Scan pasted code or text for likely leaked secrets.

Generate CORS headers/config for Nginx, Apache, Express, or Workers.

Generate time-based one-time passcodes from a Base32 secret.

Scan robots.txt for accidental disclosure of sensitive paths.

Decode a PEM CSR or certificate into its ASN.1 structure.

Generate a valid RFC 9116 /.well-known/security.txt file.