Accessibility Health Check
https://portlandmaine.gov
Getting Started
https://daylight.sonde.tech/usgov/portlandmaine-gov/
City of Portland (ME)
Getting Started
Executive Summary
Methodology
The Sonde Score is a universal 0–1000 compliance index — think of it like a credit score for accessibility. Each finding is weighted by its impact on human access: a keyboard trap (critical) counts far more than a best-practice suggestion (low). The raw penalty is normalized per page so scores are comparable across sites of any size. A harmonic curve ensures every site gets a meaningful score — no zeros, no false perfection.
where S = sensitivity (750), P = Σ(weight × count), N = pages scanned
| Tier | Weight | Examples |
|---|---|---|
| Critical | 10 | Keyboard traps, missing page language |
| High | 3 | Missing alt text, insufficient contrast |
| Medium | 1 | Heading hierarchy, unclear link purpose |
| Low | 0.25 | Best-practice suggestions |
The Sonde Score is a living standard (v0.1). We publish the methodology and invite public feedback because accessibility is too important for closed-door decisions. Your expertise makes it better.
Enter Mission Control
Review raw findings data, track changes between scans, and contribute to Sonde’s open methodology.
Nominate a Site for the Daylight Index
Know a public website that should be on the accessibility leaderboard? Nominate it — we’ll scan it and publish the results.