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Tom Utilities

Developer Utilities

Generators, converters and helpers used every day by developers.

UUID / GUID Generator Generate random version 4 UUIDs and copy them one by one or in bulk. Hash Generator Compute MD5, SHA-1, SHA-256 and SHA-512 digests of any text. Timestamp Converter Convert between Unix timestamps, ISO 8601 and human readable local dates. Regex Tester Test regular expressions against sample text and inspect every match and capture group. Text Compare / Diff Compare two blocks of text and see line level additions, removals and changes. String Case Converter Convert text between camelCase, PascalCase, snake_case, kebab-case and more. Password Generator Create strong random passwords with control over length and character sets. Color Converter Convert colors between HEX, RGB and HSL with a live preview swatch. SQL Formatter Format SQL statements into readable, consistently indented queries. Cron Expression Parser Explain a cron expression in plain language and show the next scheduled runs. QR Code Generator Create QR codes for links, text, Wi-Fi credentials or contact details and download them as PNG images. Query String Parser Parse a URL query string into readable parameters and rebuild it from key value pairs. Number Base Converter Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36. ASCII Table Browse the full ASCII table with decimal, hexadecimal, binary and character values. Byte Converter Convert between bytes, kilobytes, megabytes, gigabytes and binary units (KiB, MiB, GiB). Word & Character Counter Count characters, words, lines, sentences and paragraphs, with reading time and UTF-8 size. Sort Lines Sort lines alphabetically or in reverse, with options to remove duplicates and trim whitespace. Slug Generator Turn titles and sentences into clean URL slugs with accents removed. Lorem Ipsum Generator Generate placeholder paragraphs, sentences or words for mockups and layouts. HMAC Generator Compute HMAC signatures with SHA-1, SHA-256, SHA-384 or SHA-512 in hex or Base64. AES Encrypt / Decrypt Encrypt and decrypt text with AES-256-GCM using a password; runs entirely in your browser. Cron Expression Builder Build cron schedules with presets, a plain-language description and the next five run times. Date Difference Calculator Find the exact difference between two dates in years, months, days, hours, minutes and seconds. Time Zone Converter Convert a date and time between world time zones using the browser's built-in time zone database. URL Parser Break a URL into protocol, host, port, path, query and fragment, and inspect every query parameter. Color Palette Generator Generate tints, shades, analogous, complementary and triadic palettes from any color. CSS Gradient Generator Design linear or radial CSS gradients with a live preview and copy-ready CSS. CSS Box Shadow Generator Craft box shadows with sliders for offset, blur, spread and color, then copy the CSS. Border Radius Generator Preview and copy CSS border-radius values for each corner in pixels or percent. Color Contrast Checker Measure WCAG contrast ratios and see whether text passes AA and AAA for normal and large text. PX to REM Converter Convert between pixels, rem and em using any root font size. IPv4 Subnet Calculator Calculate the network, broadcast, mask, wildcard and usable host range for any IPv4 CIDR block. Random String Generator Generate secure random strings with custom length, character sets and ambiguous-character filtering. ULID Generator Generate sortable ULIDs and decode the timestamp from any existing ULID. Gitignore Generator Combine ready-made .gitignore templates for Node, Python, Java, Go, Rust, .NET and more. Regex Cheat Sheet A quick reference of regular expression syntax with character classes, quantifiers, anchors, groups, lookaround and escapes. Luhn Check Validator Validate credit card numbers with the Luhn algorithm and detect the network such as Visa, Mastercard or Amex. IBAN Validator Validate an IBAN using the ISO 13616 Mod-97 checksum and read the country code and check digits. Semantic Version Comparator Compare two semantic versions to see which is newer, including pre-release tags such as alpha and beta. Chmod Calculator Convert read, write and execute permissions into chmod octal and symbolic notation for owner, group and others.