Developer utilities, all in one place

Base64 decode and encode online: convert text or files to Base64, or decode Base64 back to text. Free and runs entirely in your browser.

Encode or decode full URLs or individual query parameters using percent-encoding.

Convert special characters like <, >, & and quotes to and from HTML entities.

Decode a JWT online to inspect its header, payload and claims, check the exp expiry, and verify HS256 signatures. Nothing leaves your browser.

Format, validate and beautify JSON online. Pretty print or minify with error line highlighting and a collapsible tree viewer.

Beautify or minify XML with adjustable indentation and validation error location.

Beautify SQL for MySQL, PostgreSQL, and SQL Server with keyword case and indent options.

Convert YAML to JSON and JSON to YAML online, with a built-in YAML validator that flags errors by line. Free and runs in your browser.

Convert CSV to JSON or JSON to CSV with custom delimiters and a live table preview.

View JSON as a sortable, filterable table, flatten nested objects, and export the grid to CSV.

Compare two JSON documents and see every added, removed, and changed value by path, ignoring key order.

Generate v1 or v4 UUIDs in bulk with case and hyphen formatting options.

Generate strong random passwords with a strength meter and full character-set control.

Generate placeholder text by paragraphs, sentences, or words, with optional HTML tags.

Generate SHA256, SHA1, SHA512 and MD5 hashes for text or files, and check a file's checksum against a published hash. Runs in your browser.

Generate QR codes for text, URLs, Wi-Fi credentials, or vCards, and export as PNG or SVG.

Convert text between UPPER, lower, Title Case, camelCase, snake_case, kebab-case, and PascalCase.

Count words, characters, sentences, and paragraphs live as you type, with a reading-time estimate.

Compare two blocks of text side by side or inline, with word- or line-level highlighting.

Find and replace text with optional regex, case sensitivity, and step-through control.

Escape or unescape strings for JSON, JavaScript, or SQL contexts.

Build cron expressions visually and see a plain-English explanation with upcoming run times.

Test regular expressions with live match highlighting, capture groups, and a cheat sheet.

Convert between Unix timestamps and human-readable dates across time zones.

Convert HEX to RGB, RGB to HEX, HSL, HSV and CMYK, pick colors visually, build palettes, and check WCAG contrast. Free color converter.

Write GitHub-flavored Markdown and see a live-rendered preview side by side.

What is my IP address? See your public IP, plus the approximate location and network operator for it or any IP address you look up.

Query A, AAAA, MX, TXT, NS, CNAME, and SOA records for any domain.

Fetch any URL and inspect its response status and HTTP headers.

Searchable list of HTTP status codes with meanings, common causes, and how to fix them: 200, 301, 404, 429, 500, 502, 503 and more.

Paste a User-Agent string to break it down into browser, engine, OS, and device info.

Generate SEO and Open Graph/Twitter Card meta tags for a webpage, with a live preview.

Upload an image and generate every standard favicon size, plus the HTML to include them.

Build a robots.txt visually, or paste one in to check it for common mistakes.

Check whether a URL's CORS headers would allow a browser request from another origin.

Compress an image in your browser by adjusting quality, with a live before/after size comparison.

Convert images online: PNG to JPG, JPG to PNG, WebP to PNG or JPG, and more. Free, private, and runs in your browser with no upload.

Convert an image to a Base64 data URI, or decode a data URI back into a downloadable image.

Shrink SVG markup by removing unnecessary metadata, comments, and precision.

View a photo's embedded EXIF metadata (camera, GPS, timestamps), or strip it before sharing.

Convert binary to decimal, decimal to binary, hex to decimal, decimal to hex and octal instantly. A number base converter for any size number.

Convert km to miles, kg to lbs, cm to inches, feet to meters and °C to °F. A free unit converter for length, weight and temperature.

Calculate percentages, percentage change, and reverse percentage problems.

Generate random numbers in a range, in bulk, with an optional reproducible seed.