BYTETOOLS

Random Buffer Generator

Generate cryptographically secure random bytes at any size. Output as hex, Base64 or a downloadable binary file — perfect for keys, salts, tokens and test data.

Buffer size: 32 B of cryptographically secure random data (max 16.0 MB).

What is the Random Buffer Generator?

The ByteTools Buffer Generator produces a buffer of cryptographically secure random bytes at exactly the size you choose, from a single byte up to megabytes.

  • Cryptographically secure bytes via crypto.getRandomValues
  • Size in bytes or KB, up to multi-megabyte buffers
  • Hex, Base64 or raw binary file output
  • One-click copy and .bin download
  • Chunked generation handles large buffers smoothly
  • 100% client-side and offline-capable

How to use the Random Buffer Generator

  1. 1

    Enter the buffer size and pick the unit (bytes or KB).

  2. 2

    Choose the output format: hex, Base64 or binary file.

  3. 3

    Click Generate to fill the buffer with secure random bytes.

  4. 4

    Copy the encoded string or download the buffer as a .bin file.

About the Random Buffer Generator

The ByteTools Buffer Generator produces a buffer of cryptographically secure random bytes at exactly the size you choose, from a single byte up to megabytes. Output it as a hex string, a Base64 string, or download the raw bytes as a binary file.

Developers reach for random buffers constantly: 32-byte secrets for JWT signing keys and session secrets, 16-byte salts and IVs for encryption, API tokens, nonces, and dummy binary files for testing upload limits and streaming code. Pick the size in bytes or KB, choose a format, and copy or download.

Bytes come from crypto.getRandomValues — the same OS-level CSPRNG used for real cryptography — generated in chunks entirely inside your browser. Nothing is fetched from or sent to any server.

Frequently asked questions

Are these random bytes safe to use as encryption keys or secrets?

Yes — they come from crypto.getRandomValues, which is backed by your operating system's cryptographically secure random number generator, the same source used by real crypto libraries. A 32-byte (256-bit) buffer is the standard size for symmetric keys and HMAC secrets.

How many bytes should a secret key or salt be?

Common choices: 32 bytes for a 256-bit signing or encryption key, 16 bytes for an AES IV or a password salt, and 32–64 bytes for session secrets. More bytes never hurt security, but 32 bytes is already unguessable.

What's the difference between hex and Base64 output?

They encode the same bytes differently. Hex uses 2 characters per byte (32 bytes become 64 chars) and is easiest to read and compare; Base64 uses about 1.33 characters per byte (32 bytes become 44 chars) and is more compact for config files and headers.

Why is generation done in chunks?

Browsers cap a single crypto.getRandomValues call at 65,536 bytes. For bigger buffers this tool simply calls it repeatedly and stitches the chunks together, so you can generate megabytes of randomness without errors.

Is Math.random() good enough instead of this?

Not for anything security-related. Math.random() is a predictable, non-cryptographic PRNG whose output can be reconstructed from a few samples. Always use CSPRNG output — like this tool provides — for keys, tokens, salts and nonces.

Guides for Random Buffer Generator

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