docs.flutter.dev
Ranks Overall #866 Built Awesome #684
Data from Sep 12, 2026, 1:13 AM UTC old Measured once a week · 4 runs since Aug 20, 2026
Elsewhere:
PageSpeed Insights ·
Calibre ·
Treo ·
CrUX Vis ·
Scoring Calculator ·
Wayback Machine
Lab data is measured using Lighthouse, Mobile mode unless otherwise specified. Field data is reported from Chrome UX Report (using p75 measurements).
Lighthouse Scores LAB Simulated
Metrics LAB FIELD
Field figures are the p75 across real Chrome users over a 28-day trailing window (2026-08-13 → 2026-09-09), url-level.
| Metric | Lab Simulated | Field | |||
|---|---|---|---|---|---|
| Value | Change / range | Trend | p75 | Distribution | |
| LCP CWV Largest Contentful Paint | 3.05 s needs work | ↑ +640 ms (+26.6%) 1.99 s – 3.05 s | 1.38 s good | 89.6% 5.7% 4.7% | |
| INP CWV Interaction to Next Paint — field only, no lab run can measure it | n/a | — | 149 ms good | 84.5% 13.5% 2.1% | |
| CLS CWV Cumulative Layout Shift | 0.007 good | ↓ -0.022 (-75.9%) significant 0.007 – 0.029 | 0 good | 98.3% 1% 0.7% | |
| TBT Total Blocking Time | 326 ms needs work | ↓ -36 ms (-9.9%) 214 ms – 362 ms | n/a | — | |
| FCP First Contentful Paint | 2.90 s needs work | ↑ +1043 ms (+56.2%) 1.86 s – 2.90 s | 1.21 s good | 85.4% 7.5% 7.2% | |
| Speed Index | 2.90 s good | ↑ +1043 ms (+56.2%) 1.86 s – 2.90 s | n/a | — | |
| TTFB Time to First Byte | 613 ms good | ↑ +4 ms (+0.7%) 609 ms – 621 ms | 638 ms good | 80.9% 11.2% 7.9% | |
LCP Subparts LAB Unthrottled
The subparts attribute LCP to your server, resource discovery, download, or rendering. Note that the Lab LCP shown above is a simulated throttled estimate.
LCP LAB Simulated vs LCP FIELD
The lab LCP is 2.21× the field p75 — real users likely have above-average hardware or network connectivity.
Page weight
| Metric | Value | Change / range | Trend |
|---|---|---|---|
| Page Weight | 1.19 MB | ↑ +2.9 kB (+0.3%) 1.18 MB – 1.19 MB | |
| Requests | 71 | ↓ -6 (-7.8%) significant 71 – 77 | |
| Third-party Weight | 1.00 MB | ↑ +6.6 kB (+0.7%) 988 kB – 1.00 MB | |
| Third-party CPU | 152 ms | ↓ -6 ms (-3.8%) 116 ms – 158 ms | |
| Unused JS | 175 kB | ↑ +20.8 kB (+13.9%) significant 149 kB – 175 kB | |
| Unused CSS | 11.8 kB | ↑ +320 B (+2.8%) 0 B – 11.8 kB |
By resource type
| Type | Transfer | Share | Size | Requests |
|---|---|---|---|---|
| font | 45.7% | 545 kB | 2 | |
| script | 39% | 465 kB | 39 | |
| image | 8.8% | 105 kB | 11 | |
| other | 3.5% | 42.0 kB | 13 | |
| stylesheet | 1.6% | 19.4 kB | 4 | |
| document | 1.4% | 17.1 kB | 1 | |
| Total | 1.19 MB | 71 |
Third parties 7 entities
| Entity | Transfer | Size | Main thread Simulated |
|---|---|---|---|
| Google Fonts | 548 kB | 0 ms | |
| Google Tag Manager | 322 kB | 145 ms | |
| YouTube | 100 kB | 0 ms | |
| Google CDN | 30.4 kB | 6 ms | |
| JSDelivr CDN | 3.9 kB | 1 ms | |
| All 7 | 1.00 MB | 152 ms |
Page health
| Metric | Value | Change / range | Trend |
|---|---|---|---|
| Main Thread Work | 1.75 s | ↑ +40 ms (+2.4%) 1.35 s – 1.75 s | |
| Long Tasks | 4 | → no change 4 – 5 | |
| DOM Elements | 2,219 | ↓ -3 (-0.1%) 2,219 – 2,244 | |
| Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports) | 1 | ↓ -2 (-66.7%) significant 1 – 3 | |
| A11y Failures | 1 | → no change 1 – 1 | |
| A11y Failing Nodes | 1 | → no change 1 – 1 |
Main thread work
| Task | Time | Share | Duration Simulated |
|---|---|---|---|
| script evaluation | 51% | 892 ms | |
| other | 23% | 398 ms | |
| style layout | 11% | 187 ms | |
| script parse compile | 8% | 133 ms | |
| parse HTML | 4% | 64 ms | |
| garbage collection | 3% | 46 ms | |
| paint composite render | 2% | 27 ms | |
| Total | 1.75 s |
Axe violations axe-core 4.13.0, full rule set
1 violating node across 1 rule, 792 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.
-
serious
tabindex— Elements should not have tabindex greater than zero 1 node
Accessibility failures 1 of 29 audits
-
tabindex— Some elements have a `[tabindex]` value greater than 0 1 node
Hygiene
Measurement log
Field history 25 weeks
Weekly p75 from the CrUX History API, backfilled in a single request.
| Week ending | LCP | INP | CLS | FCP | TTFB |
|---|---|---|---|---|---|
| 2026-09-05 | 1.38 s | 149 ms | 0 | 1.21 s | 650 ms |
| 2026-08-29 | 1.37 s | 144 ms | 0 | 1.21 s | 673 ms |
| 2026-08-22 | 1.39 s | 147 ms | 0 | 1.23 s | 709 ms |
| 2026-08-15 | 1.42 s | 150 ms | 0 | 1.25 s | 737 ms |
| 2026-08-08 | 1.39 s | 144 ms | 0 | 1.23 s | 709 ms |
| 2026-08-01 | 1.39 s | 145 ms | 0 | 1.21 s | 717 ms |
| 2026-07-25 | 1.35 s | 142 ms | 0 | 1.19 s | 678 ms |
| 2026-07-18 | 1.35 s | 143 ms | 0 | 1.19 s | 686 ms |
| 2026-07-11 | 1.34 s | 145 ms | 0 | 1.20 s | 695 ms |
| 2026-07-04 | 1.34 s | 141 ms | 0 | 1.22 s | 693 ms |
| 2026-06-27 | 1.36 s | 144 ms | 0 | 1.23 s | 731 ms |
| 2026-06-20 | 1.34 s | 145 ms | 0 | 1.22 s | 719 ms |
Runs
Every stored run for this URL, newest first.
| When | Scores | Perf | LCP | CLS | TBT | Weight | Runs | Spread | Bench | Took | Archive |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Sep 12, 2026, 1:13 AM UTC | 82 | 3.05 s | 0.007 | 326 ms | 1.19 MB | 3/3 | ±7 | 2,471 0% | 27s |
|
|
| Sep 4, 2026, 11:52 PM UTC | 88 | 2.41 s | 0.029 | 362 ms | 1.19 MB | 3/3 | ±18 | 2,682 +8% | 25.9s |
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|
| Aug 28, 2026, 11:30 PM UTC | 94 | 1.99 s | 0.029 | 214 ms | 1.18 MB | 3/3 | ±37 | 2,987 +20% | 25.8s |
|
|
| Aug 20, 2026, 9:30 PM UTC | 83 | 2.90 s | 0.029 | 320 ms | 1.18 MB | 3/3 | ±11 | 2,359 -5% | 26.4s |
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