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31 tools
ICS to CSV converter
Expand recurring calendar events into a date-bounded CSV, with timezone and conversion-loss details.
Open tool Files and dataJSONL to CSV converter
Convert newline-delimited JSON with heterogeneous columns, invalid-line reporting and typed cell values.
Open tool Developer toolsSHA-256 file checksum
Calculate a SHA-256 checksum locally in chunks and compare it with an expected digest.
Open tool Files and dataJSON flatten and unflatten
Flatten JSON into reversible JSON Pointer paths while preserving arrays, empty containers and data types.
Open tool Files and dataVCF to CSV converter
Convert UTF-8 vCard 3.0 and 4.0 contacts, preserving repeated fields and identifying omitted properties.
Open tool Files and dataCSV delimiter converter
Change comma, semicolon, tab or pipe delimiters without breaking quoted fields or embedded line breaks.
Open tool Media toolsSubtitle time shift
Adjust SRT or WebVTT subtitle timing with a fixed offset and optional duration multiplier.
Open tool Media toolsSRT and WebVTT converter
Convert subtitle formats with timestamp validation and clear checks for unsupported WebVTT features.
Open tool Developer toolsCron next runs by timezone
Preview five-field numeric cron schedules in an IANA timezone and compare local and UTC run times.
Open tool Developer toolsJSON Schema validator
Validate JSON locally against a Draft 2020-12 schema and inspect instance paths and constraint errors.
Open tool Files and dataYAML and JSON converter
Convert YAML 1.2 and JSON with duplicate-key detection, alias limits and explicit conversion diagnostics.
Open tool Dates and timeExcel serial date converter
Convert Excel serial numbers and dates using the explicit 1900 or 1904 system, including fractional days and Excel’s serial-60 exception.
Open tool Numbers and measurementRatio simplifier
Reduce two integer or finite-decimal values to an exact whole-number ratio using greatest-common-divisor arithmetic.
Open tool Text and developer toolsPunycode and IDN domain converter
Convert an internationalized domain between Unicode and ASCII Punycode with browser URL processing and round-trip validation.
Open tool Text and developer toolsUnicode code point inspector
Inspect Unicode code points, UTF-16 units, UTF-8 bytes and all four normalization forms: NFC, NFD, NFKC and NFKD.
Open tool Text and developer toolsIPv4 CIDR and subnet calculator
Calculate an IPv4 network, subnet mask, wildcard, address range and host count with explicit /31 and /32 handling.
Open tool Text and developer toolsIPv4 and IPv6 CIDR overlap checker
Compare two IPv4 or IPv6 network prefixes for overlap, containment, equality or adjacency with exact address ranges and counts.
Open tool Dates and timeISO week number and date converter
Convert a Gregorian date to its ISO week date, or convert an ISO week-year, week and weekday back to a Gregorian date.
Open tool Text and developer toolsHTML entity encoder and decoder
Encode HTML’s five special characters or decode semicolon-terminated named and numeric character references locally.
Open tool Text and developer toolsURL percent encoder and decoder
Encode or decode a URL component or form value with an explicit choice between percent-space and plus-space behavior.
Open tool Numbers and measurementGCD and LCM calculator
Calculate the greatest common divisor and least common multiple of up to 50 integers with exact large-integer arithmetic.
Open tool Numbers and measurementDPI and print size calculator
Convert image pixel dimensions to print dimensions, or calculate required pixels from print size and pixels per inch.
Open tool Numbers and measurementAspect ratio and resize calculator
Simplify a width-to-height ratio and calculate a matching width or height for proportional resizing without cropping.
Open tool Dates and timeTime duration calculator in UTC
Calculate elapsed time between two UTC dates or timestamps, with days, hours, minutes, seconds and milliseconds.
Open tool Numbers and measurementDecimal to fraction converter
Convert a finite decimal to an exact reduced fraction, with mixed-number output when applicable and no rounding guess.
Open tool Dates and timeUnix timestamp converter
Convert Unix seconds or milliseconds to a UTC date, or convert an explicit UTC date/time into a Unix timestamp.
Open tool Dates and timeWorld time and elapsed-time planner
Compare an interval across named time zones, resolve repeated clock times and export one UTC calendar event using pinned IANA rules.
Open tool Prayer timesWorldwide calculated prayer calendar
Find a source-listed city, town or village, review coordinates and method, and export a calculated monthly timetable.
Open tool Dates and calendarsHijri date converter
Convert Gregorian and calculated Umm al-Qura dates in either direction.
Open tool Dates and calendarsEthiopian calendar
Convert Ethiopian Amete Mihret dates, including month 13, and explore a month view.
Open tool Prayer timesPrayer-time calculator
Calculate with explicit coordinates, time zone, method and Asr convention.
Open toolLooking for a country-specific calculation?
Local prices, contribution schedules and calendar rules need a named source and an effective date.
Browse country tools