CanvasBlocker vs. Sentry AI
CanvasBlocker showed the world how websites harvest hardware graphics APIs. Sentry AI brings mathematical anti-fingerprinting to Chromium and Firefox alike, combining PRNG mathematical cloaking with 120,000+ network rules so modern web apps never break.
CanvasBlocker
Developed by kkapsner, CanvasBlocker demonstrated that websites don’t need cookies to track you - they can simply query your GPU canvas readouts. However, CanvasBlocker has limited Chromium availability, frequently breaks CAPTCHAs and graphics applications like Canva or Figma, and provides no network ad filtering or AI scraper defense.
- Deep Firefox DOM API hook coverage
- Not natively built for Chromium Manifest V3 (Chrome/Edge/Arc)
- Frequent site breakage on interactive image and map apps
- Zero network ad blocking or cookie banner automation
Sentry AI
Sentry AI elevates anti-fingerprinting into a reliable, break-free science. Using a Mulberry32 PRNG seeded by the active domain (`window.location.host + 1337`), canvas hashes remain 100% deterministic on the same site - so CAPTCHAs, Canva, and web games work seamlessly - while third-party trackers across different sites see completely uncorrelated hashes.
- Deterministic Mulberry32 PRNG noise (Zero site breakage)
- Runs universally on Chrome, Brave, Firefox, Edge, and Arc
- Integrated 120,000+ rule declarative network ad blocker
- Full WebGL, Web Audio, sub-pixel, and timezone cloaking
Anti-Fingerprinting Matrix
How dummy values compare against deterministic mathematical noise in modern browsers.
| Fingerprinting Protection Capability | CanvasBlocker | Sentry AI |
|---|---|---|
Chromium Native Manifest V3 Support Runs seamlessly on Google Chrome, Brave, Microsoft Edge, Arc, Opera | No (CanvasBlocker is primarily tailored for Firefox/Gecko) | Yes (Full native MV3 support + Dedicated Firefox Gecko AMO build) |
Legitimate App Compatibility (Canva, CAPTCHAs) Does not break Cloudflare Turnstile, Google reCAPTCHA, Figma, or image editors | High risk of breakage (Throwing errors or fake canvas buffers can break editors and CAPTCHAs) | 100% Compatible (Mulberry32 PRNG noise is deterministic per domain) |
Mathematical Noise Technique How canvas and audio readbacks are altered to defeat fingerprinting | Static dummy values or random blank noise per query (easily detected by advanced scripts) | Domain-seeded Mulberry32 PRNG (consistent within same site, scrambled cross-site) |
WebGL GPU Profile Masking Cloaks UNMASKED_RENDERER_WEBGL and UNMASKED_VENDOR_WEBGL hardware queries | Basic string spoofing | Complete V8 GPU normalization + WebGL readPixels buffer dithering |
Web Audio Acoustic Profiling Perturbs AudioContext oscillator decay measurements used by FingerprintJS | Audio buffer manipulation (can cause audible audio artifacts in media) | ±10⁻⁷ frequency micro-jitter (sub-audible with 0 impact on music/video) |
Sub-Pixel Font & Geometry Dithering Adds micro-offsets to getBoundingClientRect and measureText to prevent font enumeration | Limited font protection | ±0.0001px microscopic layout offsets applied in document_start |
Network Ad & Threat Blocking Blocks 120,000+ surveillance URLs, tracking endpoints, and ad servers | None (CanvasBlocker does not filter network requests; requires uBlock) | Included: 120,000+ threat rules evaluated in native C++ declarative engine |
Universal Cookie Consent Auto-Reject Automatically declines cookie banners and unlocks frozen page scrolling | None | Included: Multi-stage CMP negotiator (OneTrust, Cookiebot, TrustArc) |
Commercial Anti-AI Training Defense Prevents Meta, TikTok, and LLM web crawlers from scraping browsing sessions | None | Included: Training pixel blocks + Sec-GPC: 1 + X-Robots-Tag: noai injection |
Chromium Native Manifest V3 Support
Runs seamlessly on Google Chrome, Brave, Microsoft Edge, Arc, Opera
No (CanvasBlocker is primarily tailored for Firefox/Gecko)
Yes (Full native MV3 support + Dedicated Firefox Gecko AMO build)
Legitimate App Compatibility (Canva, CAPTCHAs)
Does not break Cloudflare Turnstile, Google reCAPTCHA, Figma, or image editors
High risk of breakage (Throwing errors or fake canvas buffers can break editors and CAPTCHAs)
100% Compatible (Mulberry32 PRNG noise is deterministic per domain)
Mathematical Noise Technique
How canvas and audio readbacks are altered to defeat fingerprinting
Static dummy values or random blank noise per query (easily detected by advanced scripts)
Domain-seeded Mulberry32 PRNG (consistent within same site, scrambled cross-site)
WebGL GPU Profile Masking
Cloaks UNMASKED_RENDERER_WEBGL and UNMASKED_VENDOR_WEBGL hardware queries
Basic string spoofing
Complete V8 GPU normalization + WebGL readPixels buffer dithering
Web Audio Acoustic Profiling
Perturbs AudioContext oscillator decay measurements used by FingerprintJS
Audio buffer manipulation (can cause audible audio artifacts in media)
±10⁻⁷ frequency micro-jitter (sub-audible with 0 impact on music/video)
Sub-Pixel Font & Geometry Dithering
Adds micro-offsets to getBoundingClientRect and measureText to prevent font enumeration
Limited font protection
±0.0001px microscopic layout offsets applied in document_start
Network Ad & Threat Blocking
Blocks 120,000+ surveillance URLs, tracking endpoints, and ad servers
None (CanvasBlocker does not filter network requests; requires uBlock)
Included: 120,000+ threat rules evaluated in native C++ declarative engine
Universal Cookie Consent Auto-Reject
Automatically declines cookie banners and unlocks frozen page scrolling
None
Included: Multi-stage CMP negotiator (OneTrust, Cookiebot, TrustArc)
Commercial Anti-AI Training Defense
Prevents Meta, TikTok, and LLM web crawlers from scraping browsing sessions
None
Included: Training pixel blocks + Sec-GPC: 1 + X-Robots-Tag: noai injection
The Mathematics of Deterministic PRNG Noise
Why Simple Dummy Values Fail in 2026
When an extension completely blocks or returns pure zeros for `canvas.toDataURL()`, tracking scripts easily detect the blockage (`if (canvasHash === 0) flagUserAsBlocked()`). Furthermore, web applications that rely on HTML5 Canvas (such as Cloudflare Turnstile, online whiteboard tools, photo editors, and map viewers) immediately crash or throw security exceptions.
Sentry AI's Mulberry32 Per-Origin Solution
Instead of returning blank values, Sentry AI injects micro-variations into the least significant bit (LSB) of canvas pixel color channels. The PRNG is mathematically seeded by the origin (`hash(window.location.host + 1337)`).
- Within the same domain: Calculations produce identical pixel readouts, so local application logic runs with 100% mathematical integrity.
- Across different domains: A tracker operating on site A and site B receives two completely divergent, randomized hashes, making cross-site identity linkage impossible.
Stop Hardware Profiling Without Breaking the Web
Get seamless anti-fingerprinting and 120,000+ threat filtering rules in a single install.