Test regular expressions live with match highlighting, capture groups and replace preview.
Developer Utilities
The small tools you open a dozen times a day: test a regular expression against sample text, generate a UUID, turn a Unix timestamp into a readable date, work out what a cron expression means, or convert a color between HEX, RGB and HSL.
Each utility does one job well and keeps its state in the page, so it is faster than searching for a snippet. All of them run in your browser with no account required.
Tools in this category
Build regular expressions from a library of tested patterns (email, URL, IP, dates, IBAN, Saudi/Jordan phone numbers…) and custom rules.
Get a plain-English, token-by-token explanation of any regular expression.
Generate placeholder text as paragraphs, sentences or words — Latin, Arabic or Hindi.
Generate random strings with custom length, character sets and quantity using secure randomness.
Convert timestamps (seconds, milliseconds, microseconds) to human dates and back, in any timezone.
Convert Unix epoch seconds to a readable date and get the current Unix time.
Calculate the exact difference between two dates in years, months, days, hours and total units.
Add or subtract days, weeks, months, years, hours and minutes from a date.
Convert a date and time between timezones (Riyadh, Amman, Delhi, UTC, New York, London…).
Parse and generate ISO 8601 date-time strings, durations and intervals.
Build cron expressions visually and preview the next run times.
Translate any cron expression into plain English and list upcoming run times.
Validate cron expressions field by field with precise error messages.
Generate UUID v4 (random) and v7 (time-ordered) identifiers in bulk, and validate existing ones.
Generate ULIDs (sortable, 26-character identifiers) and decode their timestamps.
Convert numbers between any bases from 2 to 36 (binary, octal, decimal, hex, base32…).
Instantly convert between decimal, binary, octal and hexadecimal with bit-level view.
Convert colors between HEX, RGB(A), HSL(A), HSB/HSV, CMYK and CSS named colors with a live preview.
Quickly convert between HEX, RGB and HSL color values.
Generate random integers or decimals in a range, with or without duplicates, using secure randomness.
Calculate percentages, percentage change, increase/decrease and what percent X is of Y.
Convert between bytes, KB, MB, GB, TB (decimal SI) and KiB, MiB, GiB (binary IEC), plus bits.
Learn more
Regular Expressions (Regex) for Beginners
Learn regex from scratch: character classes, quantifiers, anchors, groups and flags, copy-ready patterns for emails, phones and dates, and how to test safely.
UtilitiesCron Expressions Explained
Cron expressions explained field by field: minute, hour, day, month, weekday, the *, /, - and , operators, common schedules, time zones and classic mistakes.
UtilitiesWhat is a UUID? v4 vs v7, UUID vs GUID & ULID
UUIDs explained: the 128-bit format, v4 vs v7, why v7 is better for database keys, UUID vs GUID vs ULID, collision odds, and how to generate and validate them.