169 tools

Developer

Formatters, encoders, generators and testers.

Ad mockup generator Drop the creative in and see the whole unit. Ad preview tool Headline, body and image, against the tightest limits. Add prefix to lines A string on the front of every line. Apache config formatter Directive blocks indented by depth. App icon sizes One master at 1024, and what each store does to it. App store QR code generator One code, either store. Apple touch icon size 180 × 180, and never transparent. ASCII table All 128 codes in decimal, hex, octal and binary. ASCII to binary Text into eight-bit binary, one group per character. ASCII to hex Text into hex character codes. Banner ad sizes The IAB standard set, and which ones sell. Barcode generator EAN, UPC, Code 128 and more, with the check digit. Bars to seconds calculator How long a section runs at a tempo. Base64 decoder Handles missing padding and the URL-safe alphabet. Base64 encoder UTF-8 safe, with the URL-safe alphabet. Binary to ASCII Eight-bit groups back into readable text. Binary to decimal Binary to decimal, with hex and octal beside it. Binary to hex Binary to hex, grouping the bits into nibbles. Binary to IPv4 Thirty-two bits, read back as an address. Bit shift calculator Left and right shifts, and what they do to the value. Bitwise calculator AND, OR, XOR and NOT on two values, in any base. Bulk find and replace Many replacements in one pass. Calendar event QR code generator Scan to add an event to the calendar. camelCase converter Spaces out, every word after the first capitalised. Checksum calculator Hash a file and compare it to the published sum. CIDR calculator What a prefix actually covers. CIDR to netmask /24 is 255.255.255.0. Click speed test How many clicks per second, over ten seconds. Code 128 barcode generator Any text, any length, densely packed. List difference tool In one list and not the other. Compare two lists What is in one and not the other. Test card number generator Luhn-valid numbers for testing a checkout form. Card number checker Luhn checksum, brand and length. Cron expression explainer What that schedule actually does, in English. Cron expression parser What it says, and when it next fires. CSS formatter One declaration per line, or none at all. CSS minifier Comments, whitespace and the last semicolon. CSV to JSON Quoted commas and line breaks handled properly. CSV to SQL INSERT A spreadsheet into statements you can run. curl to axios The same command, as an axios config. curl to fetch A pasted curl command as JavaScript. Day of year to date Day 200 of 2026 is which date? Decimal to binary Decimal to binary, grouped so it is actually readable. Decimal to hex Decimal to hexadecimal, plus binary and octal. Decimal to octal Base 10 to base 8, with the three-bit groups shown. Diff checker Line by line, with the unchanged parts folded away. Docker Compose formatter Compose is YAML, and its indentation is meaning. EAN-13 barcode generator The world retail barcode, check digit included. Email QR code generator Opens a draft with subject and body filled in. .env formatter KEY=value, quoted only where it must be. Epoch converter Epoch time in and out, with the milliseconds question settled. Excel column letter to number AA is 27, not 26, bijective base-26. Extract domain from URL Hostnames only, www stripped, de-duplicated. Extract emails from text Every address, de-duplicated, one per line. Extract numbers from text Every number, decimals and negatives included. Extract phone numbers from text Numbers out, with an honest caveat. Extract URLs from text Links out, trailing punctuation stripped. Facebook ad preview Primary text, headline and where they cut. Facebook ad size 1080 × 1080 feed, 1080 × 1920 stories. Facebook carousel ad size 1080 × 1080 per card, all the same ratio. Favicon sizes The four files that actually cover everything. File hash checker Hash a batch of files and compare the digests. Fluid typography calculator A CSS clamp() that scales with the viewport. FPS timecode calculator Frames to timecode and back, at any frame rate. Google Ads preview Headlines and descriptions against their limits. Google display ad sizes The five that get almost all the inventory. GraphQL formatter Indented by depth, commas dropped. Hash generator MD5, SHA-1, SHA-256, SHA-512 and CRC-32 of any text. Hex to ASCII Hex character codes back into readable text. Hex to binary Hex to binary, four bits per digit, exactly. Hex to decimal Hexadecimal to decimal, with binary and octal alongside. HTML decoder Entities back to the characters they stand for. HTML encoder The five that matter, or everything above ASCII. HTML formatter Indent without touching pre or script. HTML minifier Whitespace and comments out, pre untouched. HTML table generator CSV in, a real table out. HTTP status codes Every code, and what it actually tells you. Image to Base64 A data URI, ready to paste into CSS or HTML. INI formatter Sections, keys and comments, tidied. IP CIDR calculator An address and a prefix, fully expanded. IP range to CIDR A start and end address, as the fewest blocks. IPv4 calculator One address, every representation. IPv6 calculator Expand, compress, and what the prefix means. ISBN barcode generator ISBN-13 as the EAN-13 a shop can scan. JSON flattener Nested objects to dotted paths, and back. JSON flattener Nested objects into dotted paths. JSON formatter Format, minify, validate and sort keys. JSON Lines to array NDJSON into one array, with the broken row named. JSON minifier Every byte of whitespace out. JSONPath tester An expression, and every value it matches. JSON empty value remover Nulls, empty strings and empty containers out. JSON key sorter Alphabetical at every level, so a diff is readable. JSON to CSV Every key becomes a column, nothing dropped. JSON to YAML Readable config, with the right things quoted. JSON unflattener Dotted paths back into nested objects. JSON validator Valid or not, and exactly where it fails. Julian date converter The astronomical Julian Day, not the ordinal date. JWT decoder Header, payload and expiry, signature not verified. kebab-case converter Lowercase, joined with hyphens. Network latency calculator The floor physics puts under your ping. Leaderboard ad size 728 × 90, and the mobile one that replaced it. Link preview generator Build the card, then copy the tags you need. List to comma separated A column of lines into one delimited line. Location QR code generator Coordinates that open in any maps app. MAC address formatter Colons, hyphens, Cisco dots or none. Markdown table formatter Pipes lined up, columns padded. Markdown table generator Paste a spreadsheet column, get a table. Markdown to HTML The HTML, and a preview of it. MD5 generator For checking old published checksums, not for security. Online metronome Accented downbeat, 30 to 260 BPM. Nano ID generator Short, URL-safe, and still collision-resistant. Netmask to CIDR 255.255.255.0 is /24. nginx config formatter Blocks indented by depth. Number base converter Any base from 2 to 36, in either direction. Number lines Numbered from any start, any separator. Octal to decimal Base 8 to base 10, the one file permissions use. Open Graph preview The card Facebook, LinkedIn and Slack will build. Open Graph image size 1200 × 630, the one image every platform reuses. PascalCase converter Every word capitalised, including the first. Passphrase generator Words you can actually remember, still hard to guess. Password entropy calculator What a password policy is actually worth, in bits. Password generator Strong passwords, drawn in your browser and never sent. Password strength checker An upper bound on how strong a password is, never sent. Phone QR code generator Scan to dial, no typing. QR code generator Links, Wi-Fi, contacts, no redirect, no expiry. Random PIN generator Digits only, leading zeros kept. Random token generator Hex, base32, base58, base62 or a UUID. Reaction time test Click when it turns green. Median of your attempts. Regex escaper Literal text, safe to drop into a pattern. Regex tester Matches highlighted as you type, and the pattern read back to you. SERP preview tool How your title and description will actually be cut. SHA256 generator The 64-character digest, computed as you type. Shuffle lines Random order, every arrangement equally likely. Skyscraper ad size 160 × 600, the tall one down the side. Slug generator Accents folded, everything else hyphenated. SMS QR code generator Opens a text with the number and message filled in. snake_case converter Lowercase, joined with underscores. Snapchat ad size 1080 × 1920, with three seconds to land. Social share preview One card, checked against every platform limit. SQL formatter Keyword breaks, with string literals protected. SQL IN list formatter A pasted list into a WHERE clause. SQL minifier One line, comments gone, strings untouched. SQL to CSV INSERT statements back into a spreadsheet. Strip HTML tags Tags out, and the script contents with them. Subnet calculator Network, broadcast, range and host count. Text compare Two versions side by side, differences marked. Text to CSV converter Lines and columns into a comma-separated row. Text to JSON array Lines into a properly escaped array. TOML formatter Tables flush left, keys indented under them. Tone generator 20 Hz to 18 kHz, four waveforms. TOTP secret generator A base32 shared secret and the otpauth URI to go with it. X / Twitter card preview Summary and large image, before you post. Two's complement calculator Signed binary at any bit width, with the wrap-around shown. Typing speed test Words per minute, counted the standard way. ULID generator Sortable identifiers, timestamp first. Unicode converter Every character, and what it actually is. Unicode escape converter Non-ASCII in and out of escapes. Unix timestamp converter Seconds since 1970, both directions, with millisecond detection. UPC-A barcode generator The North American retail barcode. URL encoder Component or full URL, they escape differently. UUID generator Ten at a time, from the browser’s crypto source. UUID validator Valid or not, and which version. vCard QR code generator A contact card that scans straight into the phone. WhatsApp QR code generator Opens a chat with your number and a message ready. White noise generator White, pink and brown, generated, not streamed. Wi-Fi QR code generator Guests join without typing the password. XML formatter Indent, minify and check it is well-formed. YAML formatter Reindented, and told where it broke. YAML to JSON The config subset, parsed honestly.
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