Data, time, ticks, timestamp, time span
Unix timestamp to date time. Date time to Unix timestamp. Current Unix timestamp.
C# / .NET Core / .NET Framework Ticks (DateTime.Ticks) ⇄ Date Time ⇄ Unix Timestamp three way Converter.
C# / .NET Core / .NET Framework Ticks (TimeSpan.Ticks) ⇄ Time Span (days, hours, minutes, seconds, part of second) Converter.
Count number of days from date to date. Add days to date. Subtract days from date.
Days since birthday. Days until next birthday.
Regular expression, checksum
Hash / checksum / fingerprint calculator. Hash from text (string) and file.
Network, hostname, public IP, ping
Check whether Your host / gateway responds to the ping form public network.
Find Your public IP address and hostname.
Pixel: size, count, density. Screen: resolution, aspect ratio, width, height, area.
Check the resolution of own display.
Number, text format
Decimal number to Q format number converter (web version).
Encode ASCII string to base-64 ASCII string. Decode base-64 ASCII string to ASCII string.
Name (.NET culture, English, native), ISO code (639-1, 639-2), Windows (API three letter, LCID), IETF language tag (RFC 4646).
Online reference manuals.
IT vocabulary (words, phrases, expressions, terms): abbreviations, acronyms, shortands, pithy forms.