FNV-1a Hash Generator

Generate FNV-1a hash values with support for 32-bit to 1024-bit variants. Fast, non-cryptographic hash function ideal for hash tables, checksums, and data fingerprinting.

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FNV-1a XOR-THEN-MULTIPLY ALGORITHM FAST

BYTE

Input

→

⊕ XOR

Hash XOR Byte

→

× PRIME

Multiply

→

HASH

Output

Select Hash Variant

Single Text Batch Mode

// Quick examples

Each line will be hashed separately

Output:

Embed FNV-1a Hash Generator Widget

About FNV-1a Hash Generator

Welcome to the FNV-1a Hash Generator, a free online tool to generate FNV-1a (Fowler-Noll-Vo) hash values. FNV-1a is a high-performance, non-cryptographic hash function widely used in hash tables, checksums, and data fingerprinting. This tool supports multiple bit sizes from 32-bit to 1024-bit with hexadecimal, decimal, and binary output formats.

What is FNV-1a Hash?

FNV-1a (Fowler-Noll-Vo alternate) is a non-cryptographic hash function created by Glenn Fowler, Landon Curt Noll, and Kiem-Phong Vo. It is designed to be extremely fast while providing good distribution properties for hash table implementations.

The algorithm uses a simple XOR-then-multiply approach:

Initialize: Start with a fixed offset basis value
XOR: XOR the hash with each input byte
Multiply: Multiply the result by the FNV prime
Repeat: Continue for all input bytes

FNV-1 vs FNV-1a: What is the Difference?

The main difference between FNV-1 and FNV-1a is the order of operations:

FNV-1: Multiply first, then XOR (hash = (hash * prime) XOR byte)
FNV-1a: XOR first, then multiply (hash = (hash XOR byte) * prime)

FNV-1a generally provides better avalanche characteristics, meaning small changes in input produce more significantly different hash values. This makes FNV-1a the preferred variant for most applications.

FNV-1a Parameters by Bit Size

Bit Size	FNV Prime	Offset Basis
32-bit	16777619	2166136261
64-bit	1099511628211	14695981039346656037
128-bit	309485009821345068724781371	144066263297769815596495629667062367629
256-bit	Extended parameters for low collision probability
512-bit	Extended parameters for very large datasets
1024-bit	Maximum size for extremely low collisions

Security Warning

FNV-1a is NOT suitable for cryptographic purposes. Do not use it for password hashing, digital signatures, or security-sensitive applications. For passwords, use Argon2, bcrypt, or scrypt instead.

How to Use This FNV-1a Hash Generator

Select hash variant: Choose your desired bit size from 32-bit to 1024-bit. For most applications, 64-bit provides a good balance of speed and collision resistance.
Choose input mode: Select Single Text mode for one string, or Batch mode to hash multiple strings at once (one per line).
Enter your text: Type or paste the text you want to hash. You can also use quick example buttons to test with sample data.
Select output format: Choose Hexadecimal (most common), Decimal, or Binary format for the hash output.
Generate hash: Click the Generate button to compute your FNV-1a hash. Copy the result with one click.

Best Use Cases for FNV-1a

Recommended Applications

Hash Tables: Fast key lookup in dictionaries and maps
Data Structures: Bloom filters, hash sets, hash maps
Checksums: Quick data integrity verification
Cache Keys: Generating unique cache identifiers
Data Deduplication: Identifying duplicate content
Load Balancing: Consistent hashing for server distribution

Frequently Asked Questions

What is FNV-1a hash?

FNV-1a (Fowler-Noll-Vo alternate) is a non-cryptographic hash function known for its simplicity and speed. It uses a simple XOR-then-multiply algorithm that makes it extremely fast for hash table lookups, checksums, and data fingerprinting applications.

What is the difference between FNV-1 and FNV-1a?

FNV-1 multiplies first then XORs, while FNV-1a XORs first then multiplies. FNV-1a generally provides better avalanche characteristics, meaning small changes in input produce more different hash values, making it the preferred variant for most applications.

Is FNV-1a secure for passwords?

No, FNV-1a is NOT suitable for cryptographic purposes like password hashing or digital signatures. It is a non-cryptographic hash function designed for speed, not security. For passwords, use Argon2, bcrypt, or scrypt instead.

What bit size should I use for FNV-1a?

For most hash table applications, 32-bit or 64-bit is sufficient. Use 64-bit for larger datasets to reduce collision probability. Higher bit sizes (128-1024) are useful when you need extremely low collision probability or longer hash values.

What are the best use cases for FNV-1a?

FNV-1a excels at hash table implementations, data structure indexing, checksum generation, cache key generation, data deduplication, and quick data comparison. It is ideal when speed is prioritized over cryptographic security.

References

Reference this content, page, or tool as:

"FNV-1a Hash Generator" at https://MiniWebtool.com/fnv1a-hash-generator/ from MiniWebtool, https://MiniWebtool.com/

by miniwebtool team. Updated: Jan 13, 2026

Developer API available: Run this tool from your app, automation, or agent with one JSON HTTP request. View API docs