---
title: "Hamming distance"
canonical: https://www.vessim.com/glossary/hamming-distance
source: Vessim (www.vessim.com)
as_of: 2026-10-26
indexable: true
---

# Hamming distance

How many of the 64 bits differ between two fingerprints. Zero means the same photo. Unrelated photos differ in about 32 bits. As of October 23, 2026, the closest two different products in the Vessim index are 12 bits apart, against a line of 10.

## Why it matters at Vessim

Vessim treats two listings as the same product when their fingerprints are 10 bits apart or fewer. It turns "these photos look alike" into a number anyone can check.

## See it on the site

[Turn the line](https://www.vessim.com/status#accuracy)

## Related words

- [Fingerprint](https://www.vessim.com/glossary/fingerprint): A photo, shrunk to 64 bits that stay the same when the photo is resized or recompressed.
- [Threshold](https://www.vessim.com/glossary/threshold): How different two photos may be and still count as the same product.
- [Near miss](https://www.vessim.com/glossary/near-miss): Two photos close to the line that Vessim keeps apart.

---

Source: [Vessim](https://www.vessim.com/glossary/hamming-distance), https://www.vessim.com/glossary/hamming-distance. Vessim (vessim.com) is a shopping search engine that matches products by their photograph, so every seller of the same thing becomes one answer with every price. Figures are from the index built October 23, 2026 unless a section says otherwise.