# Canvas fingerprint hash

> Render and hash your browser's canvas the way trackers do, see the hash that identifies your machine, and learn why it is stable and unique.

Source: https://mosaicbrowser.com/tools/canvas-fingerprint

## Canvas fingerprint hash

A canvas tracker draws text and shapes off-screen, reads the pixels back, and hashes them. Tiny differences in your GPU, drivers and fonts make that hash stable for your machine and often different from anyone else’s — an identifier that needs no cookie. This tool does exactly that and shows you the result, in your browser.

Your canvas, rendered and hashed.

The hashes a tracker would store.

**Nothing is uploaded.** The canvas is drawn and hashed on your machine. Reload the page and your hash should return unchanged — that stability is the whole point of the technique.

## Stable for you, different from others

The same text and shapes render slightly differently on each combination of GPU, graphics driver, operating system and installed fonts — sub-pixel anti-aliasing, rounding, font substitution. Your machine makes the same tiny choices every time, so the hash is stable; another machine usually makes different ones, so its hash differs. A tracker never has to see a cookie to recognise you again. The [canvas fingerprinting](https://mosaicbrowser.com/glossary/canvas-fingerprinting) glossary entry goes deeper.

## Noise, not a blank canvas

Blocking the canvas or returning an empty image is itself a loud signal — almost no real browser does it. The approach that holds up is per-profile noise added where the pixels are read back, so each identity has its own stable, plausible hash instead of a missing one. Mosaic does this in C++ inside its own Chromium, so the noise is consistent across every frame and worker in a profile rather than bolted on with JavaScript a page can catch.

1. **Generate the hash.** The page draws text and shapes to a hidden canvas, reads the pixels back, and hashes them — the same method a canvas tracker uses.
2. **Read your hash.** You see the canvas image, its SHA-256 hash and a WebGL render hash. The same machine and browser produce the same hash each time.
3. **Understand stability.** The tool explains why your hash is stable across reloads, and why two different machines usually hash differently.

### What is canvas fingerprinting?

A tracker draws text and shapes to an off-screen canvas and reads the pixels back. Tiny differences in how your GPU, drivers and fonts render produce a value that is stable for your machine and often differs between machines — an identifier that needs no cookie.

### Why is my hash the same every time?

Because the same machine and browser render the canvas the same way. That stability is exactly what makes it useful to a tracker: reload the page and the hash returns.

### Does Mosaic just block the canvas?

No — a blocked or empty canvas is itself a signal. Mosaic adds per-profile noise to canvas and WebGL readback inside the engine, so each profile has its own stable, plausible hash instead of a missing one.

## Every account its own browser. One price for all of them.

Free holds 3 profiles and 10 profile creations, with no card. Pro is $49 a month for any number, or $490 a year with 2 months free. Try it for 14 days; cancel before day 14 and you pay nothing.

Mosaic is a desktop app

Email yourself the link and open it on your computer.