Check library · Speed and Core Web Vitals
Image has no width and height
Why it matters
Missing dimensions cause layout shift as the image loads.
What to do about it
Set explicit width and height attributes.
The engine generates this fix itself using the set_image_dimensions strategy. It arrives in your queue as a complete artefact, because an incomplete fix never reaches the queue, and once you approve it the change is pushed and the page re-fetched to confirm it is live.
How it is weighted
These are the values the scoring actually uses, not a description of them. Priority is derived from all three rather than chosen, which is why a high-impact, low-effort finding surfaces above a severe one that would take a quarter to fix.
- Severity
- low
- Impact
- 25% of the weight this category can carry
- Effort
- 10%, where 100% is a project rather than a change
- Confidence
- 80% that a hit is a real problem rather than a pattern we misread
- Area
- Speed and Core Web Vitals
Other checks in Speed and Core Web Vitals
highServer response is slowslow_responseneeds a decisionmediumPage weight is largeheavy_pageneeds a decisionmediumVery large JavaScript payloadexcessive_javascriptneeds a decisionmediumRender-blocking stylesheets and scriptsrender_blocking_resourcesneeds a decisionlowImage uses a legacy formatimage_legacy_formatfix writtenlowBelow-the-fold images load eagerlyimage_no_lazy_loadingfix written
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