pkg.go.dev

https://pkg.go.dev/

Ranks Overall #1,343 Developer Tooling #57 Package Managers #10

Data from Sep 14, 2026, 5:54 AM UTC 26h old Measured every 2 days · 11 runs since Aug 25, 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).

Stack

Hosted by Google Frontend

Filmstrip LAB Throttled

How the page drew during the measured load, at 8 points across 5.45 s. Compare this filmstrip against another site.

681 ms
1.36 s
1.89 s
2.73 s
3.41 s
4.09 s
4.77 s
5.45 s

Lighthouse Scores LAB Simulated

Performance

↑ +1 (+1%)

Accessibility

no change

Best Practices

↓ -23 (-23%)

SEO

no change

Metrics LAB FIELD

Core Web Vitals: passing 3 of 3 assessed from real Chrome users.

Field figures are the p75 across real Chrome users over a 28-day trailing window (2026-08-15 → 2026-09-11), url-level.

Metric	Lab Simulated	Field
LCP CWV Largest Contentful Paint	1.26 s good	↑ +4 ms (+0.3%) 1.25 s – 3.56 s	1.35 s good	93.4% 4.8% 1.9%
INP CWV Interaction to Next Paint — field only, no lab run can measure it	n/a	—	119 ms good	87.2% 11.2% 1.6%
CLS CWV Cumulative Layout Shift	0.005 good	↓ -0.001 (-16.7%) 0.005 – 0.011	0 good	100% 0% 0%
TBT Total Blocking Time	116 ms good	↓ -29 ms (-20%) significant 90 ms – 159 ms	n/a	—
FCP First Contentful Paint	1.26 s good	↑ +4 ms (+0.3%) 1.25 s – 2.09 s	1.20 s good	90.7% 5.6% 3.7%
Speed Index	1.42 s good	↑ +160 ms (+12.7%) 1.25 s – 2.09 s	n/a	—
TTFB Time to First Byte	662 ms good	↑ +4 ms (+0.6%) 644 ms – 688 ms	634 ms good	84.5% 11.9% 3.6%

Metric

Lab Simulated

Field

Value

Change / range

Trend

p75

Distribution

LCP CWV Largest Contentful Paint

1.26 s good

↑ +4 ms (+0.3%) 1.25 s – 3.56 s

1.35 s good

93.4% 4.8% 1.9%

INP CWV Interaction to Next Paint — field only, no lab run can measure it

n/a

—

119 ms good

87.2% 11.2% 1.6%

CLS CWV Cumulative Layout Shift

0.005 good

↓ -0.001 (-16.7%) 0.005 – 0.011

0 good

100% 0% 0%

TBT Total Blocking Time

116 ms good

↓ -29 ms (-20%) significant 90 ms – 159 ms

n/a

—

FCP First Contentful Paint

1.26 s good

↑ +4 ms (+0.3%) 1.25 s – 2.09 s

1.20 s good

90.7% 5.6% 3.7%

Speed Index

1.42 s good

↑ +160 ms (+12.7%) 1.25 s – 2.09 s

n/a

—

TTFB Time to First Byte

662 ms good

↑ +4 ms (+0.6%) 644 ms – 688 ms

634 ms good

84.5% 11.9% 3.6%

LCP Subparts LAB Throttled

The subparts attribute LCP to your server, resource discovery, download, or rendering. They come from one throttled load, the same one as the filmstrip, so they add up to that load’s LCP rather than the simulated Lab LCP above.

resource load duration 1.19 s

time to first byte 620 ms

resource load delay 71 ms

element render delay 18 ms

LCP LAB Simulated vs LCP FIELD

Lab 1.26 s

Field p75 1.35 s

The lab LCP is 0.93× the field p75 — real users likely have similar hardware or network connectivity to the lab test.

Page weight

Metric	Value	Change / range
Page Weight	555 kB	↑ +3.3 kB (+0.6%) 545 kB – 555 kB
Requests	36	↑ +2 (+5.9%) significant 34 – 39
Third-party Weight	352 kB	↑ +1.2 kB (+0.4%) 343 kB – 352 kB
Third-party CPU	90 ms	↓ -8 ms (-8.5%) significant 75 ms – 106 ms
Unused JS	165 kB	↓ -1.7 kB (-1%) 162 kB – 166 kB
Unused CSS	21.7 kB	→ no change 21.7 kB – 21.7 kB

Metric

Value

Change / range

Trend

Page Weight

555 kB

↑ +3.3 kB (+0.6%) 545 kB – 555 kB

Requests

↑ +2 (+5.9%) significant 34 – 39

Third-party Weight

352 kB

↑ +1.2 kB (+0.4%) 343 kB – 352 kB

Third-party CPU

90 ms

↓ -8 ms (-8.5%) significant 75 ms – 106 ms

Unused JS

165 kB

↓ -1.7 kB (-1%) 162 kB – 166 kB

Unused CSS

21.7 kB

→ no change 21.7 kB – 21.7 kB

By resource type

Type	Share	Size	Requests
script	72.7%	399 kB	5
image	14.2%	78.1 kB	24
stylesheet	6.7%	36.6 kB	2
document	6.3%	34.9 kB	1
other	0.1%	447 B	3
Total		555 kB	36

Third parties 4 entities

Entity	Transfer	Size	Main thread Simulated
Google Tag Manager	script	330 kB	78 ms
Google Analytics		21.8 kB	12 ms
Google/Doubleclick Ads		22 B	0 ms
Other Google APIs/SDKs		21 B	0 ms
Total		352 kB	90 ms

Entity

Transfer

Size

Main thread Simulated

Google Tag Manager

script

330 kB

78 ms

Google Analytics

21.8 kB

12 ms

Google/Doubleclick Ads

22 B

0 ms

Other Google APIs/SDKs

21 B

0 ms

Total

352 kB

90 ms

Without JavaScript

The same load, photographed twice at 412×823: once with scripts disabled, once as rendered.

5.9% of pixels differ — they are nearly identical. A shifted layout counts as difference, so a <noscript> banner alone can account for a large figure.

Page health

Metric	Value	Change / range
Main Thread Work	865 ms	↓ -73 ms (-7.8%) 782 ms – 1.08 s
Long Tasks	3	→ no change 2 – 4
DOM Elements	383	→ no change 383 – 383
Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports)	16	→ no change 16 – 16
A11y Failures	4	→ no change 4 – 4
A11y Failing Nodes	16	→ no change 16 – 16

Metric

Value

Change / range

Trend

Main Thread Work

865 ms

↓ -73 ms (-7.8%) 782 ms – 1.08 s

Long Tasks

→ no change 2 – 4

DOM Elements

383

→ no change 383 – 383

Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports)

→ no change 16 – 16

A11y Failures

→ no change 4 – 4

A11y Failing Nodes

→ no change 16 – 16

Main thread work

Task	Share	Duration Simulated
script evaluation	47%	405 ms
other	35%	304 ms
style layout	8%	69 ms
script parse compile	5%	43 ms
paint composite render	2%	16 ms
garbage collection	2%	15 ms
parse HTML	2%	15 ms
Total		865 ms

Task

Time

Duration Simulated

script evaluation

47%

405 ms

other

35%

304 ms

style layout

69 ms

script parse compile

43 ms

paint composite render

16 ms

garbage collection

15 ms

parse HTML

15 ms

Total

865 ms

Axe violations axe-core 4.13.0, full rule set

16 violating nodes across 5 rules, 580 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.

critical image-alt — Images must have alternative text 6 nodes
serious link-name — Links must have discernible text 6 nodes
minor aria-allowed-role — ARIA role should be appropriate for the element 2 nodes
moderate landmark-unique — Landmarks should have a unique role or role/label/title (i.e. accessible name) combination 1 node
moderate region — All page content should be contained by landmarks 1 node

Accessibility failures 4 of 31 audits

image-alt — Image elements do not have `[alt]` attributes 6 nodes
link-name — Links do not have a discernible name 6 nodes
target-size — Touch targets do not have sufficient size or spacing. 3 nodes
label-content-name-mismatch — Elements with visible text labels do not have matching accessible names. 1 node

Best Practices failures 2 of 17 audits

third-party-cookies — Uses third-party cookies 1 item
inspector-issues — Issues were logged in the `Issues` panel in Chrome Devtools 1 item

SEO failures 1 of 9 audits

image-alt — Image elements do not have `[alt]` attributes 6 items

Hygiene

HTTPS HSTS CSP Clickjacking protection Origin isolation Trusted Types bfcache h2

Measurement log

Field history 25 weeks

Weekly p75 from the CrUX History API, backfilled in a single request.

Week ending	LCP	INP	FCP	TTFB
2026-09-05	1.28 s	122 ms	1.15 s	585 ms
2026-08-29	1.30 s	119 ms	1.16 s	597 ms
2026-08-22	1.34 s	118 ms	1.17 s	627 ms
2026-08-15	1.32 s	116 ms	1.19 s	597 ms
2026-08-08	1.34 s	108 ms	1.20 s	605 ms
2026-08-01	1.29 s	106 ms	1.16 s	586 ms
2026-07-25	1.24 s	106 ms	1.14 s	558 ms
2026-07-18	1.23 s	105 ms	1.10 s	565 ms
2026-07-11	1.23 s	106 ms	1.10 s	579 ms
2026-07-04	1.25 s	111 ms	1.13 s	587 ms
2026-06-27	1.21 s	111 ms	1.11 s	586 ms
2026-06-20	1.23 s	116 ms	1.13 s	607 ms

Week ending

LCP

INP

CLS

FCP

TTFB

2026-09-05

1.28 s

122 ms

1.15 s

585 ms

2026-08-29

1.30 s

119 ms

1.16 s

597 ms

2026-08-22

1.34 s

118 ms

1.17 s

627 ms

2026-08-15

1.32 s

116 ms

1.19 s

597 ms

2026-08-08

1.34 s

108 ms

1.20 s

605 ms

2026-08-01

1.29 s

106 ms

1.16 s

586 ms

2026-07-25

1.24 s

106 ms

1.14 s

558 ms

2026-07-18

1.23 s

105 ms

1.10 s

565 ms

2026-07-11

1.23 s

106 ms

1.10 s

579 ms

2026-07-04

1.25 s

111 ms

1.13 s

587 ms

2026-06-27

1.21 s

111 ms

1.11 s

586 ms

2026-06-20

1.23 s

116 ms

1.13 s

607 ms

Runs

Every stored run for this URL, newest first.

When	Perf	LCP	CLS	TBT	Weight	Runs	Spread	Bench	Took	Archive
Sep 14, 2026, 5:54 AM UTC	99	1.26 s	0.005	116 ms	555 kB	3/3	±5	3,185 +28%	53.8s	Wayback
Sep 11, 2026, 11:25 PM UTC	98	1.26 s	0.006	145 ms	552 kB	3/3	±0	2,310 -7%	56.5s	Wayback
Sep 9, 2026, 8:30 PM UTC	98	1.78 s	0.005	143 ms	551 kB	3/3	±0	2,300 -7%	28.2s	Wayback
Sep 7, 2026, 7:03 PM UTC	99	1.25 s	0.006	135 ms	551 kB	3/3	±1	2,339 -6%	27.3s	Wayback
Sep 5, 2026, 12:47 PM UTC	98	1.69 s	0.006	159 ms	551 kB	3/3	±5	2,484 0%	29.3s	Wayback
Sep 4, 2026, 10:50 AM UTC	98	1.28 s	0.006	146 ms	548 kB	3/3	±1	2,447 -1%	27.6s	Wayback
Sep 3, 2026, 1:09 AM UTC	99	1.55 s	0.005	90 ms	549 kB	3/3	±1	3,021 +22%	25.4s	Wayback
Sep 1, 2026, 11:08 PM UTC	94	2.71 s	0.006	126 ms	549 kB	3/3	±6	2,640 +6%	27.8s	Wayback
Aug 31, 2026, 9:26 PM UTC	87	3.56 s	0.006	148 ms	548 kB	3/3	±21	2,488 0%	29s	Wayback
Aug 26, 2026, 7:03 PM UTC	98	1.29 s	0.006	138 ms	545 kB	3/3	±34	2,439 -2%	28.6s	Wayback
Aug 25, 2026, 4:36 PM UTC	94	2.88 s	0.011	147 ms	545 kB	3/3	±3	2,436 -2%	28s	Wayback

When

Scores

Perf

LCP

CLS

TBT

Weight

Runs

Spread

Bench

Took

Stack

Filmstrip LAB 🐢 Throttled

Lighthouse Scores LAB 🤖 Simulated

Metrics LAB FIELD

LCP Subparts LAB 🐢 Throttled

LCP LAB 🤖 Simulated vs LCP FIELD

Page weight

By resource type

Third parties 4 entities

Without JavaScript

Page health

Main thread work

Axe violations axe-core 4.13.0, full rule set

Accessibility failures 4 of 31 audits

Best Practices failures 2 of 17 audits

SEO failures 1 of 9 audits

Hygiene

Measurement log

Field history 25 weeks

Runs

Filmstrip LAB Throttled

Lighthouse Scores LAB Simulated

LCP Subparts LAB Throttled

LCP LAB Simulated vs LCP FIELD