Your Tests Pass.
Your UX Breaks.
CI is green. Deploy shipped. But users can't checkout because a promo banner covers the button on mobile.
Capture real rendered UI state — with salience scoring — so LLMs catch regressions that E2E tests miss.
E2E Tests Say
- ✓ Button exists
- ✓ Button clickable
- ✓ Form submits
All pass. Ship it.
Semantic Check Says
- ⚠ "Pay" button: salience 95%
- ⚠ Promo banner: salience 70%
- ⚠ Occlusion detected: 60%
CTA blocked on mobile. Regression.
"We don't ask the model what matters — we tell it."
SiFR pre-weights elements by salience. LLM interprets, not discovers. That's why CSS noise is ignored, but hidden CTAs trigger alerts.
What Tests Miss, This Catches
Layout Regressions
- • Banner covers checkout button
- • Products pushed below the fold
- • CMS update breaks grid
- • A/B variant hides CTA
Responsive Breaks
- • Desktop OK, mobile broken
- • Tablet layout overlap
- • Third-party widget covers form
- • Chat widget blocks action
Security Issues
- • Defacement detection
- • Phishing overlay on login
- • Content injection in critical areas
- • Unexpected DOM changes
How It Compares
| Issue | E2E Tests | Visual Diff | E2LLM |
|---|---|---|---|
| Button covered by banner | ✗ Pass | ⚠ Noise | ✓ Alert |
| Content pushed off-screen | ✗ Pass | ✗ Pass | ✓ Alert |
| Mobile-only break | ✗ Miss | ⚠ Maybe | ✓ Alert |
| CSS font change | ✓ Ignore | ✗ 500 alerts | ✓ Ignore |
How It Works
Capture
SiFR extracts DOM with salience scores. Not raw HTML — semantic structure.
Interpret
LLM describes functional state. What users can do, not what code says.
Compare
Detect meaning changes, not pixel changes. Functional regressions only.
The Loop
No screenshots. No guessing. Real state → Real answers.
100% Local
Nothing leaves your browser. Ever. No tracking, no cloud.
Token Efficient
Compact JSON. 2KB instead of 10MB HTML. Built for LLM context.
Playwright Ready
Programmatic API for CI/CD integration. Post-deploy checks.
LLM Agnostic
Works with Claude, GPT, Grok, Llama. Your choice.
Your tests check if code works.
This checks if users can use it.
Free. Open source. Install in seconds.
Prompts & Examples · Curated prompts for QA, accessibility, security checks.
Your tests check if code works.
This checks if users can use it.