Random String Generator

A single random string drawn from the charset you choose. Set Length from 1 to 256 and pick a Charset: lowercase, uppercase, mixed case, digits, lowercase + digits, full alphanumeric, or a fully custom pool you type in. Runs in your browser. For multiple passwords with toggles, see the password generator.

Input
Line 1:1 LF cloud_done Saved locally
Result Random String
0 lines 0 chars

A random string with the charset you want

Pick a length between 1 and 256, then pick the character pool. The Charset dropdown offers seven presets: Lowercase (a-z), Uppercase (A-Z), Mixed Case (both), Digits (0-9), Lowercase + Digits (the default), Alphanumeric (letters + digits, both cases), and Custom (the contents of the Custom field).

When you switch to Custom, every character you type into the Custom input becomes part of the pool, including spaces and symbols. If you pick Custom but leave the field empty, the generator falls back to lowercase plus digits.

Output is one string in the output panel. Closer to a password generator? Use the password generator for bulk runs with on/off toggles for symbol and digit groups. Need a UUID instead? Use the UUID generator.

How to use random string generator

  1. 1Open the tool. The input panel can be left empty.
  2. 2Set Length from 1 to 256 in the option panel.
  3. 3Pick a Charset from the dropdown, or choose Custom and fill Custom with your own pool.
  4. 4The output panel shows the random string.
  5. 5Click Copy to grab it.

Keyboard shortcuts

Drive TextResult without touching the mouse.

Shortcut Action
Ctrl FOpen the find & replace panel inside the input Plus
Ctrl ZUndo the last input change
Ctrl Shift ZRedo
Ctrl Shift EnterToggle fullscreen focus on the editor Plus
EscClose find & replace, or exit fullscreen
Ctrl KOpen the command palette to jump to any tool Plus
Ctrl SSave current workflow draft Plus
Ctrl PRun a saved workflow Plus

What this tool actually does

Seven charset presets

Charset options: Lowercase, Uppercase, Mixed Case, Digits, Lowercase + Digits (default), Alphanumeric, Custom. Each preset selects a fixed pool you can verify in the settings table below.

Length up to 256

Set Length from 1 to 256 characters. Each position is drawn independently from the chosen pool.

Custom charset for arbitrary alphabets

Pick Custom in Charset and fill Custom with whatever characters you want. Useful for alphabets your data layer requires (hex only, base32, a particular emoji set, and so on).

Empty custom fallback

If you pick Custom but leave the Custom field empty, the pool falls back to lowercase plus digits so you never get a zero-length pool. Fill the field to take control.

Browser-only via Math.random

Each character is drawn with Math.random(). That is suitable for IDs, fixture data, and casual tokens. Not cryptographic; for security-grade tokens use a server CSPRNG.

Worked example

Length 16, charset Lowercase + Digits (the default). Each character is one independent draw from a-z0-9.

Input
Length: 16 - Charset: Lowercase + Digits
Output
k7r2mq4n8h0p3wzx

Settings reference

Option Effect on output
Length Characters in the output string. Default 16, minimum 1, maximum 256.
Charset = Lowercase Pool is abcdefghijklmnopqrstuvwxyz.
Charset = Uppercase Pool is ABCDEFGHIJKLMNOPQRSTUVWXYZ.
Charset = Mixed Case Pool is a-z + A-Z (52 chars).
Charset = Digits Pool is 0123456789.
Charset = Lowercase + Digits Pool is a-z0-9 (36 chars). The default.
Charset = Alphanumeric Pool is a-z + A-Z + 0-9 (62 chars).
Charset = Custom Pool is whatever you type into Custom. Empty falls back to lowercase + digits.
Random source Math.random(). Not cryptographic.

FAQ

How is this different from the password generator?
The password generator emits multiple passwords at once with toggles for letter case, digits, and symbols. This tool emits a single string with a single charset preset (or a custom pool you type in).
Can I generate a hex string?
Yes. Pick Custom as Charset and type 0123456789abcdef into the Custom field. Set Length to whatever you need.
What if I pick Custom but leave the field empty?
The generator falls back to lowercase plus digits so the output is never blank. Fill Custom to drive the pool yourself.
Is the output sent anywhere?
No. The generator runs entirely in your browser via JavaScript. Nothing is uploaded, nothing is logged.
Is this safe to use as an API key?
Treat it as low-stakes random text. Suitable for fixture data and IDs. For real API keys or session tokens, generate them server-side with a CSPRNG.