zeman/perfmap
Front-end performance heatmap bookmarklet. observed · 2026-08-28
Health v2 · maintenance only
32/100
- Activity 0
- Release rhythm 35
- Longevity 100
Flags: no_releases no_license
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.
- gap_med: n/a
- age_days: 4368
- days_rel: n/a
- days_push: 3401
- n_releases_24m: 0
Adoption not part of the score
3766 stars · 126 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
PerfMap is a bookmarklet and Chrome extension that overlays a performance heatmap on a webpage, visualizing when images finished loading during page load using the Resource Timing API. It helps front-end developers understand perceived load performance at a glance.
Use cases
- visualize when images load during page load
- audit front-end performance of a webpage
- identify slow-loading images hurting user experience
- overlay a load-time heatmap on any site
- analyze resource timing in the browser
When to choose
- you want a quick, zero-install visual check of image load times on any page
- you prefer a bookmarklet or lightweight extension over a full profiling suite
- you need to communicate load-time user experience to non-technical stakeholders
When to avoid
- you need full waterfall analysis of all resource types, not just images
- you require automated or CI-based performance testing
- your browser lacks Resource Timing API support
- you need actively maintained tooling with ongoing fixes
Facets
plugin · maturity maintenance
monitoring data-visualization developer-tools web-development frontend performance browser-extensions browser browser-extension bookmarklet performance-heatmap resource-timing-api page-load-analysis web-performance javascript
1 source
- readme: https://github.com/zeman/perfmap · fetched 2026-08-28 · f9139a5f39ad
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| zeman/perfmap | main | 32 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem