12daysofweb.dev
Data from Aug 20, 2026, 3:36 PM UTC — 27h old.
Built Awesome · 1 measurement · since Aug 20, 2026 · last attempt 27h
Stack
Detected on the same page load as the accessibility pass — the generator
from <meta name="generator"> or the shape of the page,
the host from response headers.
Core Web Vitals field data, origin-level
Real Chrome users, 28-day window (2026-07-19 → 2026-08-15). From the backfilled CrUX history rather than this measurement, which predates the API key. This is what Google measures you on.
Scores
Lab metrics Lighthouse, mobile
| Metric | Current | Previous | Change | Best | Worst | Trend |
|---|---|---|---|---|---|---|
| LCP Largest Contentful Paint | 1.58 s | — | — | 1.58 s | 1.58 s | |
| CLS Cumulative Layout Shift | 0 | — | — | 0 | 0 | |
| TBT Total Blocking Time | 5 ms | — | — | 5 ms | 5 ms | |
| FCP First Contentful Paint | 812 ms | — | — | 812 ms | 812 ms | |
| Speed Index | 812 ms | — | — | 812 ms | 812 ms | |
| TTFB Time to First Byte | 610 ms | — | — | 610 ms | 610 ms |
What LCP is made of
A flat LCP number tells you something regressed. The subparts tell you whether it was the server, resource discovery, the download, or rendering.
Field history 25 weeks
Weekly p75 from the CrUX History API, backfilled in a single request.
| Week ending | LCP | INP | CLS | FCP | TTFB |
|---|---|---|---|---|---|
| 2026-08-15 | — | — | — | — | — |
| 2026-08-08 | — | — | — | — | — |
| 2026-08-01 | — | — | — | — | — |
| 2026-07-25 | — | — | — | — | — |
| 2026-07-18 | — | — | — | — | — |
| 2026-07-11 | — | — | — | — | — |
| 2026-07-04 | — | — | — | — | — |
| 2026-06-27 | — | — | — | — | — |
| 2026-06-20 | — | — | — | — | — |
| 2026-06-13 | — | — | — | — | — |
| 2026-06-06 | — | — | — | — | — |
| 2026-05-30 | — | — | — | — | — |
Page weight
| Metric | Current | Previous | Change | Best | Worst | Trend |
|---|---|---|---|---|---|---|
| Page Weight | 54.3 kB | — | — | 54.3 kB | 54.3 kB | |
| Requests | 13 | — | — | 13 | 13 | |
| Third-party Weight | 2.7 kB | — | — | 2.7 kB | 2.7 kB | |
| Third-party CPU | 2 ms | — | — | 2 ms | 2 ms | |
| Unused JS | 0 B | — | — | 0 B | 0 B | |
| Unused CSS | 0 B | — | — | 0 B | 0 B |
By resource type
Third parties 1 entities
2.7 kB transferred, 2 ms of main thread time. This is the number most likely to regress without anyone on your team shipping anything.
Page health
| Metric | Current | Previous | Change | Best | Worst | Trend |
|---|---|---|---|---|---|---|
| Main Thread Work | 350 ms | — | — | 350 ms | 350 ms | |
| Long Tasks | 1 | — | — | 1 | 1 | |
| DOM Elements | 158 | — | — | 158 | 158 | |
| Axe Violations Violating nodes from a full axe run — stricter than Lighthouse's subset | 1 | — | — | 1 | 1 | |
| A11y Failures | 0 | — | — | 0 | 0 | |
| A11y Failing Nodes | 0 | — | — | 0 | 0 |
Main thread work
Axe violations axe-core 4.13.0, full rule set
1 violating node across 1 rule, 231 passing. This is a standalone axe run, stricter than the subset Lighthouse folds into its score above — and it is the second tiebreaker in the ranking.
-
moderate
landmark-unique— Landmarks should have a unique role or role/label/title (i.e. accessible name) combination 1 node
Hygiene
Changes rarely — which is exactly why a change is worth noticing.
Measurement log
Every stored run for this URL, newest first. Failures are kept as records — "this site was down on Tuesday" is data too.
| When | Perf | LCP | CLS | TBT | Weight | Runs | Spread | Bench | Took |
|---|---|---|---|---|---|---|---|---|---|
| Aug 20, 2026, 3:36 PM UTC | 100 | 1.58 s | 0 | 5 ms | 54.3 kB | 3/3 | ±3 | 2,294 | 22.8s |
Embed this score
Live below, then the markup that produces it. Drop that on any page to show
12daysofweb.dev's scores, updated whenever this instance
re-measures — more about the component. Don’t forget to bundle the speedlify-score.js component code into your site!
<speedlify-score speedlify-url="https://zachleat.github.io/speedlify2/" url="https://12daysofweb.dev/"></speedlify-score>