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UUID Generator

Generate UUIDs in versions 1, 3, 4, 5, 6 and 7, one at a time or in bulk. Pick a version, set how many you need, and regenerate with one click. Name-based versions take a namespace and a name, and the result copies as a plain list.

Everything runs locally in your browser. Your data never leaves your device.

122 random bits. The default choice for identifiers.

Result

0 UUIDs

Next steps

Send this tool's output straight into another tool.

UUID Decoder

Paste a UUID to see what it carries: version, variant, and for time-based versions the exact timestamp, clock sequence and node. Also shows the raw bytes, the 128-bit integer and the URN form.

devuuid

Text Case Converter

Convert text into every case at once: title case in the APA, AP, Chicago, MLA, Bluebook, AMA and NYT styles, sentence case, upper, lower, camelCase, snake_case, kebab-case and more.

textconverter

Word & Character Counter

Count words, characters, sentences, paragraphs, lines and more as you type, with estimated reading and speaking time.

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Dedupe Lines

Remove duplicate lines from a list or text, keeping the first occurrence. Optionally ignore case and whitespace, or drop blank lines too.

textdev

Find and Replace

Replace text in two modes: plain find and replace all, or regular expressions with flag controls and capture group references like $1.

textdev

Text Diff

Compare two texts and see every added, removed and changed line highlighted, side by side or inline, with the changed words marked within each line. Ignore case, whitespace or blank lines, read a summary of how much changed, and export the result as a unified diff.

textdev

Base64 Encoder & Decoder

Decode Base64 to text or encode text to Base64. Paste into the top box, read the result below, and flip the direction with one click. Handles Unicode correctly, reads URL-safe Base64, and shows binary payloads as a hex dump you can download.

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Number Base Converter

Convert numbers between binary, octal, decimal, hexadecimal and any base up to 36. Type into any field and the others update as you go. Handles huge integers without losing precision and accepts 0x, 0b and 0o prefixes.

devconvertercalculator

Scientific Notation Converter

Convert between scientific notation and full numbers as you type. Reads 1.23e5, 1.23 × 10^5 and plain numbers, shows the value written out, in normalized scientific notation and in engineering notation, and can round to any number of significant digits.

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About the UUID Generator Tool

This tool generates UUIDs in every version you are likely to meet: the random version 4, the sortable version 7, the time-based versions 1 and 6, the name-based versions 3 and 5, and the special nil and max values.

Random and time-based versions come one at a time or in bulk, up to 500 per click. The name-based versions take a namespace and a name instead, and always return the same UUID for the same input.

What you can do

  • Generate a random version 4 UUID, or hundreds at once.
  • Generate sortable version 7 UUIDs for database keys.
  • Derive a version 3 or 5 UUID from a namespace and a name.
  • Generate time-based version 1 and 6 UUIDs.
  • Copy a single UUID, or copy and download a whole list.
  • Switch the output to uppercase.

How to use the UUID Generator

  1. 1Pick the version. Version 4 is the safe default, version 7 if the ids should sort by creation time.
  2. 2Set how many you need and click Regenerate for a fresh batch.
  3. 3For version 3 or 5, choose a namespace and type the name to hash.
  4. 4Copy the result, or download the list as a text file.

Which version to pick

Version 4 is pure randomness and the right answer for most identifiers. Version 7 puts a Unix timestamp in front of the randomness, so ids created later sort later, which keeps database indexes happy. Versions 1 and 6 encode a Gregorian timestamp plus a node id, with 6 being the modern layout that sorts naturally. Versions 3 and 5 hash a namespace and a name, so the same input always maps to the same UUID, useful when two systems must independently agree on an id. Version 5 (SHA-1) is preferred over 3 (MD5).

To look inside any of these, paste one into the UUID Decoder.

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UUID Decoder

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Aspect Ratio Calculator

Enter a resolution to get its simplified aspect ratio, or start from a ratio and one side to get the missing dimension. Knows the common ratios like 16:9, 4:3 and 21:9 and shows how close your size is to each.

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