Wren Beta — what that means

uu.nl

readable

C Acceptable. Readable, but working against you

Loading speed is diagnostic only; it does not affect this grade or search ranking.

SubjectWeightScore
Interruption 35.71% 100
Readability 28.57% 29
Accessibility and keyboard 21.43% 99
Stability and weight 14.29% 97

This letter rests on 100% of the grade. Every subject was measured, including article readability and accessibility. How this is worked out.

uu.nl
Largest paint
1.2s
Paywall
none
Ad requests
6
Tracker requests
10
Page weight
1.3 MB
Readability
14px type · 1.4 line height · 34 characters per line · 11.2:1 contrast (over an image)
Accessibility
no automated violations detected
Green hosting
not measured
Measured
2026-08-31

Observed interruptions

Ad and tracker counts above are network requests, not counts of visible ads or separate companies. They do not affect the interruption score.

Assessed 3 sampled pages. The largest detected ad area was 0% of a sampled viewport. No qualifying obstructive prompts were detected.

This is a sample, not a promise that the whole site has no interruptions. Ad detection can miss formats and content outside the sampled view. Older scans did not check visibility or overlapping ad rectangles as thoroughly. The score uses the strongest observed deduction, so one panel is not penalized under multiple names. How interruptions are scored.

The type, and who can use it

Measured on 1 rendered page; latest measurement 2026-09-05. Every number is a mechanical fact about the page, not a judgment of its design.

WhatMeasuredThe bar
Body type size 14px 16px, the browser default
Characters per line 34 45–90
Line height 1.43 1.5 (WCAG 1.4.8)
Text contrast 11.2:1 — over a background image, so not scored 4.5:1 (WCAG AA), 7:1 (AAA)
Text column 24% of the window at least 45%
Reflows at phone width yes WCAG 1.4.10
Dark mode no noted, not scored
Automated accessibility checks no automated violations detected WCAG 2.1 A and AA, via axe-core
Keyboard no trap; focus visible on 93% of stops never trapped, always visible
Structure main landmark, 1 h1, no skipped heading levels a main landmark, one h1, no skips
Alt text 100% of 10 content images described every content image
Reader mode parses parses (Firefox’s Readability)

Automated accessibility checks catch an estimated 30–40% of real problems, so “no automated violations detected” is a floor, not a certificate. We never say “accessible”. How these are scored.

Measurement dates

Oldest evidence 50 days old. At least one subject is due for rechecking (30 days or older). Dates refer to the evidence, never the card rebuild.

Measurement history

Newest 4 saved observations. Each describes a sampled page at that time; older, failed or held observations do not override the current reviewed card. Raw automated findings may have been superseded by later review or detector replay. No previous grade is inferred.

Read dated observations
  1. — Readability and accessibility observation; prose source p; desktop type 14px; phone overflow not observed
    https://www.uu.nl/androclusgebouw
    Evidence source: readability-top5000.jsonl · observation 8c51d5f4f758
  2. — Access observation: pass
    https://www.uu.nl/onderzoek/copernicus-institute-of-sustainable-development/gaim-langdurige-empowerment-met-energie-applicaties-door-inclusief-game-ontwerp-kunstmatige
    Evidence source: verdicts-top5000.jsonl · observation 513e168964b0
  3. — Access observation: pass
    https://www.uu.nl/en/education/centre-for-academic-teaching-and-learning/preparing-for-in-depth-work-lecture-with-the-e-modules-in-xerte
    Evidence source: verdicts-top5000.jsonl · observation 3edb41269bb3
  4. — Access observation: pass
    https://www.uu.nl/onderwijs/centre-for-academic-teaching-and-learning/samenwerkingen-laten-beoordelen-via-feedbackfruits-group-member-evaluation
    Evidence source: verdicts-top5000.jsonl · observation 0d4794ab9caf

How we know

Pages rendered3
Site verdicterrors dropped; majority of remaining; ties to the stricter verdict; active reviewed exclusions override admission
Figures shownnumeric measurements generally use medians; interruption costs, overflow, keyboard traps and accessibility failures retain the strongest observed finding
Cited by2,557 encyclopedia articles

Think this is wrong? It may well be — the measurements cover only a handful of pages. Any reviewed admission decision and its dated evidence are shown above. Re-measurement on request is not built yet, so there is no button here that would do anything. When it exists it will be free and it will be on this page.