Can I change the length or generate a batch?

Yes. Length takes 1 to 4,096 code points and quantity takes 1 to 10,000, subject to the 1,000,000-byte output ceiling. The tool refuses an oversized request with the count that fits. It does not silently truncate a batch.

Are the generated strings unique?

Strings are independent draws; duplicates are possible and are not removed. Short strings over a small alphabet repeat readily. Longer strings reduce the probability but do not prove uniqueness. UUID v4/v7 also have collision limits; neither is a uniqueness certificate.

What is saved between visits?

No. It uses the browser cryptographic source with no user seed, remote API or reproducible sequence. Letters may repeat within a string and strings may repeat within a batch. Copy/export is a manual browser workflow, separate from JavaScript, Python, Java or database code generation. Only settings explicitly changed are remembered; opening this preset does not replace unrelated saved choices.

Random Binary String Generator

Generate random bit strings from the exact alphabet 01. The page starts at 32 bits, represented as 32 text characters. This is textual binary output, not a raw four-byte file or a conversion of an input number. Set quantity up to 10,000 strings within the 1,000,000-byte batch ceiling. The browser draws each character locally; repeats are possible. Copy all uses one value per line, and CSV exports one string per row.

ReadyYour strings appear here

Drawn in this tab the moment the page is ready

Include

Your own

Exclude

Length

How many

Alphabet

2 characters

Length

Strings

Output

329 bytes

Three settings people come here for

32 hex charactersa custom alphabet of 0 to 9 and a to f
8 character codescapitals and digits, look-alikes removed
40 characters, all 94letters, digits and every ASCII symbol

The alphabet is built in order: the sets you turn on, then the characters you type in Your own, then everything in Exclude is taken back out. Duplicates are kept once, and a character that cannot be printed is dropped, so every string is one line you can paste anywhere. A batch is capped at 1,000,000 bytes: a larger request is refused with the number of strings that would fit, rather than quietly cut short.

Made here, kept here. Every character comes from crypto.getRandomValues on your own device, mapped onto your alphabet by rejection sampling, so no position in it is favoured. Nothing you type and nothing drawn is sent anywhere, put into an analytics event or written into a link, and the only thing this page remembers between visits is your settings.

Accuracy. Drawn from the browser's cryptographic random source with rejection sampling, so every character of your alphabet is equally likely. These are random strings for testing and identifiers, not a password policy: a strong password also needs a length and a store you trust.

Common questions

What does the starting alphabet contain?: Generate random bit strings from the exact alphabet 01. The page starts at 32 bits, represented as 32 text characters. This is textual binary output, not a raw four-byte file or a conversion of an input number.
Can I change the length or generate a batch?: Yes. Length takes 1 to 4,096 code points and quantity takes 1 to 10,000, subject to the 1,000,000-byte output ceiling. The tool refuses an oversized request with the count that fits. It does not silently truncate a batch.
Are the generated strings unique?: Strings are independent draws; duplicates are possible and are not removed. Short strings over a small alphabet repeat readily. Longer strings reduce the probability but do not prove uniqueness. UUID v4/v7 also have collision limits; neither is a uniqueness certificate.
What is saved between visits?: No. It uses the browser cryptographic source with no user seed, remote API or reproducible sequence. Letters may repeat within a string and strings may repeat within a batch. Copy/export is a manual browser workflow, separate from JavaScript, Python, Java or database code generation. Only settings explicitly changed are remembered; opening this preset does not replace unrelated saved choices.

Drawn from the browser's cryptographic random source with rejection sampling, so every character of your alphabet is equally likely. These are random strings for testing and identifiers, not a password policy: a strong password also needs a length and a store you trust.