Free Developer Tools

A complete, searchable ASCII reference for codes 0–127, showing the decimal, hexadecimal, octal, and binary value of every character plus control-code names.

Find the exact aspect ratio of any width and height pair, or scale one dimension to match a target while keeping the original proportions perfectly intact.

Generate standard 1D barcodes — Code 128, EAN-13, UPC, Code 39 and more — with a live preview, and download them as PNG or SVG, all in your browser.

Convert text to Base64 and back. Works with full Unicode via UTF-8, and runs entirely in your browser so nothing is uploaded.

Convert any binary number to its decimal equivalent instantly, with a full positional breakdown showing the value of every bit. Works in both directions — decimal back to binary too.

Instantly convert between bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes — using both decimal (SI) and binary (IEC) prefixes. Everything runs in your browser with no data uploaded.

Tick read, write and execute for owner, group and other to instantly get the octal permission value, the symbolic rwx string and the exact chmod command.

Paste a code snippet and turn it into a polished, shareable image — with window chrome, a dark or light theme, syntax colors, and a gradient backdrop — in your browser.

Paste a card number to run the Luhn checksum and detect its brand by prefix and length. It runs entirely in your browser for developers testing formats — no card data is ever stored or sent.

Build a standard 5-field cron expression from each field, pick a common preset, and read a plain-English explanation of exactly when it will run.

Set the radius of each corner of a box independently in pixels or percent, watch a live preview update as you type, and copy ready-to-paste CSS that collapses to the shortest valid border-radius shorthand.

Drag the sliders to design a CSS box-shadow, watch it update on a live preview box, and copy the exact box-shadow declaration with one click.

Build linear and radial CSS gradients with a visual editor. Pick a gradient type, set the angle, add as many color stops as you want, watch a live preview update in real time, and copy clean, ready-to-paste background CSS.

Convert CSV or TSV into a clean JSON array of objects, or turn a JSON array back into CSV. Pick your delimiter, choose whether the first row is a header, and download the result.

Build and visualize CSS cubic-bezier() easing curves with four control values, a live curve preview, ready-made presets, and one-click copyable output.

A fast, secure hash generator that creates cryptographic digests from any text input. Choose from SHA-256 (default), SHA-1, SHA-384, or SHA-512 algorithms—all processed in your browser with zero data collection.

Enter two pairs of latitude/longitude coordinates to instantly compute the straight-line great-circle distance using the Haversine formula — the standard method used in navigation, mapping APIs, and geospatial development.

Convert any HSL color value to its RGB equivalent instantly, with hex code output and a live color preview — no sign-up required.

Encode reserved and non-ASCII characters into safe HTML entities, or decode named, decimal, and hexadecimal entities back into the original text. Everything runs locally in your browser, so nothing you paste ever leaves your device.

Paste JSON to pretty-print it, validate it, or minify it. Errors are reported with a clear message so you can find the problem fast.

Paste JSON to strip every byte of unnecessary whitespace and get the smallest valid equivalent, with a live before/after byte-size and percent-saved comparison.

Paste JSON to check whether it is valid. If it isn't, you get the error plus the line and column where it breaks; if it is, you get a clean formatted copy.

A JWT decoder transforms the cryptic Base64-encoded segments of a JSON Web Token into readable JSON and human-friendly dates. Copy any JWT, paste it in, and instantly see what claims it contains—perfect for debugging authentication, understanding token payloads, and checking expiration without needing the secret key.

Write or paste Markdown and get clean, sanitized HTML with a live side-by-side preview — GitHub-flavored, copy-ready, and processed entirely in your browser.

Instantly convert any integer between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) — all four results update live as you type.

Convert any pixel value to REM units for responsive CSS in seconds. Set a custom base font size to match your project's root font size exactly.

Turn a link or any text into a QR code and download it as a PNG. It’s generated in your browser — what you enter is not uploaded — and there’s no watermark.

Test JavaScript regular expressions instantly in your browser. Enter a pattern, add flags like g for global or i for case-insensitive, and see all matches highlighted with counts. Perfect for debugging regex before you use it in code.

Calculate the relative luminance of any color (0 = absolute black, 1 = absolute white) using the WCAG 2.x linearization formula, essential for contrast ratio and accessibility compliance checks.

Paste a messy SQL query and get it cleanly formatted and indented, with control over the dialect, keyword case, and indent width — all live in your browser.

Instantly calculate subnet details from any IPv4 CIDR notation — network address, broadcast address, subnet mask, first and last usable host, and total host count.

Convert text to 8-bit binary and decode binary back to text, with optional decimal and hex output. Runs entirely in your browser, so nothing is uploaded.

Convert a Unix timestamp to a readable date — in both UTC and your local time — or turn a date into a timestamp. Handles seconds and milliseconds.

Encode text for safe use in a URL, or decode a percent-encoded URL back to readable text. Runs in your browser with full Unicode support.