Tools

IPv4Subnet Calculator

Work out network address, broadcast, usable host range and mask from any IPv4 address and prefix length.

L2MAC Address Formatter

Reformat a MAC address between colon, hyphen and Cisco dot notation, and read the bits that tell you what kind of address it is.

TCP / UDPPort Reference

Filterable list of the TCP and UDP ports that actually come up in day-to-day work, searchable by number, service or protocol.

Base64 / URL / HTMLEncoder and Decoder

Convert text to and from Base64, Base64url, URL percent-encoding and HTML entities, with correct handling of non-ASCII characters.

JSON Web TokenJWT Decoder

Read the header and claims of a JSON Web Token, with timestamps resolved to real dates and expiry checked against now.

JSONJSON Formatter

Reindent, minify and validate JSON, with the parse error pointed at the line and column that broke it.

SHA-1 / 256 / 384 / 512Hash Generator

Produce SHA-1, SHA-256, SHA-384 and SHA-512 digests of text or a file, computed locally by the browser's own crypto engine.

RAID 0 / 1 / 5 / 6 / 10RAID Calculator

Usable capacity, fault tolerance and rebuild exposure for RAID 0, 1, 5, 6, 10, 50 and 60, with the TB against TiB gap made explicit.

B / KB / MiB / GiBData Size Converter

Convert between decimal and binary data units, and work out how long a transfer takes at a given link speed.

EntropyPassword Generator

Generate random strings or passphrases using the browser's cryptographic random source, with the real entropy shown for each.

5-fieldCron Explainer

Read a five-field cron expression back in plain English and see the next run times, so you can check a schedule before it goes live.

Unix timeEpoch Converter

Convert Unix timestamps to readable dates and back, in both UTC and local time, with seconds and milliseconds handled automatically.

Entra IDEntra ID Role Lookup

Searchable reference for Microsoft Entra ID built-in roles - what each one can actually do, its risk level, and a lower-privilege alternative where one exists.

Conditional AccessConditional Access Rule Simulator

Define simplified Microsoft Entra ID Conditional Access policies and simulate a sign-in against them to see which apply and what grant controls result.