blog.stackblitz.com

https://blog.stackblitz.com/

Ranks Overall #1,699 Astro Showcase #197

Data from Oct 2, 2026, 6:45 AM UTC 16h old Measured once a month · 1 run since Oct 2, 2026

Elsewhere: PageSpeed Insights · Calibre · Treo · CrUX Vis · Tame the Bots · 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

Built with Astro 4.15.4

Uses React

Hosted by Netlify

Lighthouse Scores LAB Simulated

Performance

no change

Accessibility

no change

Best Practices

no change

SEO

no change

Metrics LAB FIELD

Core Web Vitals: failing 2 of 3 assessed from real Chrome users.

Field figures are the p75 across real Chrome users over a 28-day trailing window (2026-09-02 → 2026-09-29), origin-level.

Metric	Lab Simulated	Field
LCP CWV Largest Contentful Paint	4.66 s poor	— 4.66 s – 4.66 s	2.81 s needs work	71.2% 15.1% 13.7%
INP CWV Interaction to Next Paint — field only, no lab run can measure it	n/a	—	—	—
CLS CWV Cumulative Layout Shift	0 good	— 0 – 0	0 good	98.2% 0% 1.9%
TBT Total Blocking Time	454 ms needs work	— 454 ms – 454 ms	n/a	—
FCP First Contentful Paint	775 ms good	— 775 ms – 775 ms	2.02 s needs work	69.9% 17% 13.2%
Speed Index	775 ms good	— 775 ms – 775 ms	n/a	—
TTFB Time to First Byte	605 ms good	— 605 ms – 605 ms	1.42 s needs work	45.8% 39.3% 14.9%

Metric

Lab Simulated

Field

Value

Change / range

Trend

p75

Distribution

LCP CWV Largest Contentful Paint

4.66 s poor

— 4.66 s – 4.66 s

2.81 s needs work

71.2% 15.1% 13.7%

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

n/a

—

CLS CWV Cumulative Layout Shift

0 good

— 0 – 0

0 good

98.2% 0% 1.9%

TBT Total Blocking Time

454 ms needs work

— 454 ms – 454 ms

n/a

—

FCP First Contentful Paint

775 ms good

— 775 ms – 775 ms

2.02 s needs work

69.9% 17% 13.2%

Speed Index

775 ms good

— 775 ms – 775 ms

n/a

—

TTFB Time to First Byte

605 ms good

— 605 ms – 605 ms

1.42 s needs work

45.8% 39.3% 14.9%

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.

element render delay 111 ms

resource load duration 9 ms

resource load delay 9 ms

time to first byte 7 ms

LCP LAB Simulated vs LCP FIELD

Lab 4.66 s

Field p75 2.81 s

The lab LCP is 1.66× the field p75 — real users likely have above-average hardware or network connectivity.

Page weight

Metric	Value	Change / range
Page Weight	2.28 MB	— 2.28 MB – 2.28 MB
Requests	45	— 45 – 45
Third-party Weight	533 kB	— 533 kB – 533 kB
Third-party CPU	205 ms	— 205 ms – 205 ms
Unused JS	242 kB	— 242 kB – 242 kB
Unused CSS	0 B	— 0 B – 0 B

Metric

Value

Change / range

Trend

Page Weight

2.28 MB

— 2.28 MB – 2.28 MB

Requests

— 45 – 45

Third-party Weight

533 kB

— 533 kB – 533 kB

Third-party CPU

205 ms

— 205 ms – 205 ms

Unused JS

242 kB

— 242 kB – 242 kB

Unused CSS

0 B

— 0 B – 0 B

By resource type

Type	Share	Size	Requests
image	70.2%	1.60 MB	23
script	25.6%	583 kB	11
font	3.6%	82.5 kB	4
document	0.3%	7.2 kB	1
stylesheet	0.3%	6.5 kB	2
other	<0.1%	488 B	4
Total		2.28 MB	45

Third parties 3 entities

Entity	Transfer	Size	Main thread Simulated
Google Tag Manager	script	531 kB	204 ms
Google/Doubleclick Ads		2.7 kB	1 ms
Other Google APIs/SDKs		126 B	0 ms
Total		533 kB	205 ms

Entity

Transfer

Size

Main thread Simulated

Google Tag Manager

script

531 kB

204 ms

Google/Doubleclick Ads

2.7 kB

1 ms

Other Google APIs/SDKs

126 B

0 ms

Total

533 kB

205 ms

Page health

Metric	Value	Change / range
Main Thread Work	1.44 s	— 1.44 s – 1.44 s
Long Tasks	5	— 5 – 5
DOM Elements	304	— 304 – 304
Axe Violations Violating nodes from a full Axe CLI run (more than Lighthouse reports)	35	— 35 – 35
A11y Failures	7	— 7 – 7
A11y Failing Nodes	28	— 28 – 28

Metric

Value

Change / range

Trend

Main Thread Work

1.44 s

— 1.44 s – 1.44 s

Long Tasks

— 5 – 5

DOM Elements

304

— 304 – 304

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

— 35 – 35

A11y Failures

— 7 – 7

A11y Failing Nodes

— 28 – 28

Main thread work

Task	Share	Duration Simulated
script evaluation	52%	750 ms
other	21%	304 ms
style layout	13%	188 ms
script parse compile	10%	147 ms
paint composite render	1%	21 ms
parse HTML	1%	20 ms
garbage collection	0%	7 ms
Total		1.44 s

Task

Time

Duration Simulated

script evaluation

52%

750 ms

other

21%

304 ms

style layout

13%

188 ms

script parse compile

10%

147 ms

paint composite render

21 ms

parse HTML

20 ms

garbage collection

7 ms

Total

1.44 s

Axe violations axe-core 4.13.0, full rule set

35 violating nodes across 9 rules, 378 passing. This is a standalone Axe CLI run and is stricter than the subset Lighthouse already includes.

serious color-contrast — Elements must meet minimum color contrast ratio thresholds 10 nodes
Offending elements (5 of 10)
1. .category-posts[data-astro-cid-2d2avbyi=""]:nth-child(1) > .post__heading[data-astro-cid-2d2avbyi=""] > .post__heading__link[data-astro-cid-2d2avbyi=""]
```
<a href="/categories/news-and-announcements" class="post__heading__link" data-astro-cid-2d2avbyi=""> View all <span class="long" data-astro-cid-2d2avbyi="">from News</span> </a>
```
2. .category-posts[data-astro-cid-2d2avbyi=""]:nth-child(1) > .post__list[data-astro-cid-2d2avbyi=""] > .layout__feature.show__authorImage.post-list > .post-list__post > .post__content > .post__description
```
<p class="post__description" data-astro-cid-csj4u5ke="">We are thrilled to announce that Cloudflare is backing pkg.pr.new’s data infrastructure, enabling us to sustainably scale preview package relea…
```
3. .category-posts[data-astro-cid-2d2avbyi=""]:nth-child(1) > .post__list[data-astro-cid-2d2avbyi=""] > .direction__column.hide__coverImage.post-list > .post-list__post:nth-child(1) > .post__content > .post__description
```
<p class="post__description" data-astro-cid-csj4u5ke="">We're doubling down on our support to Open Source in 2025 with a 100K fund targeted at web infrastructure and Bolt dependencies.</p>
```
4. .category-posts[data-astro-cid-2d2avbyi=""]:nth-child(1) > .post__list[data-astro-cid-2d2avbyi=""] > .direction__column.hide__coverImage.post-list > .post-list__post:nth-child(2) > .post__content > .post__description
```
<p class="post__description" data-astro-cid-csj4u5ke="">The third edition of ViteConf was another incredible community party. ViteConf 24 showed how much the Vite Ecosystem keeps growing and evolving…
```
5. .category-posts[data-astro-cid-2d2avbyi=""]:nth-child(1) > .post__list[data-astro-cid-2d2avbyi=""] > .direction__column.hide__coverImage.post-list > .post-list__post:nth-child(3) > .post__content > .post__description
```
<p class="post__description" data-astro-cid-csj4u5ke="">We’re excited to welcome VoidZero. Their work in Rolldown, Oxc, and Vite will have a profound effect on the Web ecosystem.</p>
```

serious aria-hidden-focus — ARIA hidden element must not be focusable or contain focusable elements 6 nodes

Offending elements (5 of 6)

.layout__cover > .post-list__post > .post__image[aria-hidden="true"]

<a class="post__image" href="/posts/cloudflare-backing-pkg-pr-new-data-infrastructure/" aria-hidden="true" data-astro-cid-csj4u5ke="">

.show__meta.show__authorImage.post-list > .post-list__post:nth-child(1) > .post__image[href$="bolt-100k-oss-fund/"][aria-hidden="true"]

<a class="post__image" href="/posts/bolt-100k-oss-fund/" aria-hidden="true" data-astro-cid-csj4u5ke=""> <img src="/_astro/hero.Cn1TnLmU_1hEmBN.jpg" alt="" style="aspect-ratio:2" data-astro-cid-csj4u5…

.show__meta.show__authorImage.post-list > .post-list__post:nth-child(2) > .post__image[href$="viteconf-2024-recap/"][aria-hidden="true"]

<a class="post__image" href="/posts/viteconf-2024-recap/" aria-hidden="true" data-astro-cid-csj4u5ke=""> <img src="/_astro/hero.WoxfdrKF_Z1kuxUA.jpg" alt="" style="aspect-ratio:2" data-astro-cid-csj4…

.show__meta.show__authorImage.post-list > .post-list__post:nth-child(3) > .post__image[aria-hidden="true"]

<a class="post__image" href="/posts/unbundling-the-js-ecosystem/" aria-hidden="true" data-astro-cid-csj4u5ke=""> <img src="/_astro/hero.B3pZchEe_ZNdfcS.jpg" alt="" style="aspect-ratio:2" data-astro-c…

.category-posts[data-astro-cid-2d2avbyi=""]:nth-child(1) > .post__list[data-astro-cid-2d2avbyi=""] > .layout__feature.show__authorImage.post-list > .post-list__post > .post__image[aria-hidden="true"]
```
<a class="post__image" href="/posts/cloudflare-backing-pkg-pr-new-data-infrastructure/" aria-hidden="true" data-astro-cid-csj4u5ke="">
```

moderate region — All page content should be contained by landmarks 6 nodes

Offending elements (5 of 6)

section:nth-child(3)

<section class="container" data-astro-cid-xhq7nhw4="">

img[src$="bolt-comment.svg"]

<img src="/logo/bolt-comment.svg" data-astro-cid-62cl7j3s="">

.container__content[data-astro-cid-62cl7j3s=""] > h2

<h2 data-astro-cid-62cl7j3s="">Subscribe to StackBlitz Updates</h2>

p[data-astro-cid-62cl7j3s=""]

<p data-astro-cid-62cl7j3s="">A newsletter from StackBlitz covering engineering achievements, product features, and updates from the community.</p>

#email

<input type="text" id="email" name="email" placeholder="Your email" class="_signupForm__input_fvfkp_44">

serious link-name — Links must have discernible text 4 nodes

Offending elements

.nav-top__title__logo

<a class="nav-top__title__logo" href="https://stackblitz.com" data-astro-cid-2w66rqv5=""></a>

a[href$="stackblitz"][target="_blank"][rel="nofollow"]:nth-child(1)

<a href="https://twitter.com/stackblitz" target="_blank" rel="nofollow" data-astro-cid-ak3upacl=""> <div class="_icon_1vecz_1 _twitter_1vecz_65" style="width:24px;height:24px;background-color:var(--s…

a[href$="stackblitz"][target="_blank"][rel="nofollow"]:nth-child(2)

<a href="https://github.com/stackblitz" target="_blank" rel="nofollow" data-astro-cid-ak3upacl=""> <div class="_icon_1vecz_1 _github_1vecz_57" style="width:24px;height:24px;background-color:var(--sbb…

a[href$="stackblitz"][target="_blank"][rel="nofollow"]:nth-child(3)

<a href="https://discord.gg/stackblitz" target="_blank" rel="nofollow" data-astro-cid-ak3upacl=""> <div class="_icon_1vecz_1 _discord_1vecz_49" style="width:24px;height:24px;background-color:var(--sb…

critical image-alt — Images must have alternative text 3 nodes

Offending elements

img[src$="bolt-color.svg"]

<img src="/logo/bolt-color.svg" data-astro-cid-xhq7nhw4="">

img[src$="bolt-comment.svg"]

<img src="/logo/bolt-comment.svg" data-astro-cid-62cl7j3s="">

.footer__logo

<img class="footer__logo" src="/logo/stackblitz-logo-color.svg" data-astro-cid-ak3upacl="">

serious listitem — <li> elements must be contained in a <ul> or <ol> 3 nodes

Offending elements

.copyright-links > li:nth-child(1)

<li data-astro-cid-ak3upacl="">© 2025 StackBlitz Inc.</li>

.copyright-links > li:nth-child(2)

<li data-astro-cid-ak3upacl=""><a href="https://stackblitz.com/terms-of-service" data-astro-cid-ak3upacl="">Terms of Service</a></li>

.copyright-links > li:nth-child(3)

<li data-astro-cid-ak3upacl=""><a href="https://stackblitz.com/privacy-policy" data-astro-cid-ak3upacl="">Privacy Policy</a></li>

critical button-name — Buttons must have discernible text 1 node

Offending element

._openMenuButton_1uy8v_59

<button class="_openMenuButton_1uy8v_59"><div class="_icon_1vecz_1 _bars_1vecz_9" style="width:18px;height:18px;background-color:var(--sbb-light-foreground)"></div></button>

moderate heading-order — Heading levels should only increase by one 1 node
Offending element
1. h5
```
<h5 data-astro-cid-xhq7nhw4="">Explore more from StackBlitz</h5>
```
moderate page-has-heading-one — Page should contain a level-one heading 1 node
Offending element
1. html
```
<html lang="en">
```

Accessibility failures 7 of 17 audits

color-contrast — Background and foreground colors do not have a sufficient contrast ratio. 10 nodes
aria-hidden-focus — `[aria-hidden="true"]` elements contain focusable descendents 6 nodes
link-name — Links do not have a discernible name 4 nodes
image-alt — Image elements do not have `[alt]` attributes 3 nodes
listitem — List items (`<li>`) are not contained within `<ul>`, `<ol>` or `<menu>` parent elements. 3 nodes
button-name — Buttons do not have an accessible name 1 node
heading-order — Heading elements are not in a sequentially-descending order 1 node

Best Practices failures 2 of 19 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 10 audits

image-alt — Image elements do not have `[alt]` attributes 3 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	CLS	FCP	TTFB
2026-09-26	2.83 s	—	0	2.01 s	1.40 s
2026-09-19	2.81 s	—	0	2.00 s	1.36 s
2026-09-12	2.36 s	—	0	1.80 s	1.18 s
2026-09-05	2.35 s	—	0	1.71 s	1.07 s
2026-08-29	2.24 s	228 ms	0	1.71 s	1.15 s
2026-08-22	2.23 s	235 ms	0	1.71 s	1.10 s
2026-08-15	2.24 s	232 ms	0	1.72 s	1.03 s
2026-08-08	2.24 s	—	0	1.73 s	1.14 s
2026-08-01	2.29 s	140 ms	0	1.72 s	1.10 s
2026-07-25	2.43 s	179 ms	0.010	1.84 s	1.15 s
2026-07-18	2.50 s	250 ms	0.010	1.84 s	1.17 s
2026-07-11	2.54 s	250 ms	0.010	2.00 s	1.25 s

Runs

Every stored run for this URL, newest first.

When	Scores	Perf	LCP	CLS	TBT	Weight	Runs	Spread	Bench	Took	Archive
Oct 2, 2026, 6:45 AM UTC		72	4.66 s	0	454 ms	2.28 MB	3/3	±32	2,464 -1%	26.1s	Wayback

When

Scores

Perf

LCP

CLS

TBT

Weight

Runs

Spread

Bench

Took

Stack

Lighthouse Scores LAB 🤖 Simulated

Metrics LAB FIELD

LCP Subparts LAB 🐇 Unthrottled

LCP LAB 🤖 Simulated vs LCP FIELD

Page weight

By resource type

Third parties 3 entities

Page health

Main thread work

Axe violations axe-core 4.13.0, full rule set

Accessibility failures 7 of 17 audits

Best Practices failures 2 of 19 audits

SEO failures 1 of 10 audits

Hygiene

Measurement log

Field history 25 weeks

Runs

Lighthouse Scores LAB Simulated

LCP Subparts LAB Unthrottled

LCP LAB Simulated vs LCP FIELD