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https://deepseek.com

Performance

· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
96
GRADE
A
FIX
1
REVIEW
5
PASS
7
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
88
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
96
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
91
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

1.07 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

1.40 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

193 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.001

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

1.07 s

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

1.67 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
15
7 PASS 5 REVIEW 1 FIX
D
JS Bundles
Action
10 scripts, 308 KB unused
FIX
10 scripts, 308 KB unused
Warning::
https://a0fea896111e.5368fe9c.eu-west-1.token.awsw...: 274 KB unused (55%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://deepseek.com/_next/static/chunks/8848-d252...: 34 KB unused (61%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 308 KB
308 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/challenge.js502 KB274 KB (55%)✓3rd
https://deepseek.com/_next/static/chunks/8848-d252791ce07a3fe3.js56 KB34 KB (61%)✓1st
https://deepseek.com/_next/static/chunks/webpack-2e06bec4baf15881.js6 KB—✓1st
https://deepseek.com/_next/static/chunks/c56f180e-6001d5763de6082d.js54 KB—✓1st
https://deepseek.com/_next/static/chunks/6714-6422be53e1640400.js29 KB—✓1st
https://deepseek.com/_next/static/chunks/main-app-0138e63140c237ca.js1 KB—✓1st
https://deepseek.com/_next/static/chunks/2278-6827556f92234ddf.js30 KB—✓1st
https://deepseek.com/_next/static/chunks/app/%5Blocale%5D/layout-761353d13bda8476.js2 KB—✓1st
https://deepseek.com/_next/static/chunks/5069-6affb9693b43a1d0.js30 KB—✓1st
https://deepseek.com/_next/static/chunks/app/%5Blocale%5D/page-a8799f32b82d85c2.js23 KB—✓1st

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

B
Page Weight Budget
1.0 MB transferred, 24 requests
REVIEW
1.0 MB transferred, 24 requests
Info::
Page weighs 2.5 MB (1.0 MB transferred)
Warning::
JavaScript is 734 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 734 KB
Info::
24 HTTP requests
Info::
Estimated 0.22 g CO2 per page load
1.0 MB / 2.4 MB budget
1.0 MB transferred
24 requests
0.22 g CO2 per page load
JavaScript 734.2 KiB 69%
Other 205.8 KiB 19%
Fonts 47.7 KiB 4%
Images 46.6 KiB 4%
HTML 19.1 KiB 2%
CSS 14.5 KiB 1%
Other 2.0 KiB 0%
Other 540 B 0%
0 2.4 MB 4.9 MB
Under budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

B
Third-Party Impact
52% third-party, 0 ms blocking
REVIEW
52% third-party, 0 ms blocking
Warning::
Third-party code accounts for 52% of page weight (551.3 KiB of 1.0 MiB)
Info::
Third-party blocking time is low (0 ms)
48%
52%
First-party Third-party
B
JS Execution Cost
814ms total JS execution
REVIEW
814ms total JS execution
Warning::
https://a0fea896111e.5368fe9c.eu-west-1.token.awsw...: 329ms CPU time
Info::
https://deepseek.com/: 197ms CPU time
Info::
Unattributable: 109ms CPU time
Info::
https://deepseek.com/_next/static/chunks/6714-6422...: 100ms CPU time
Info::
https://deepseek.com/_next/static/chunks/c56f180e-...: 79ms CPU time
Warning::
Third-party scripts: 437ms (54% of total)

Main Thread Breakdown

Script Evaluation 55% Style & Layout 17% Other 13% Script Parsing & Compilation 12%
ScriptTotalScriptingParse/CompileParty
https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/challenge.js329ms235ms63ms3rd
https://deepseek.com/197ms18ms7ms1st
Unattributable109ms46ms0ms3rd
https://deepseek.com/_next/static/chunks/6714-6422be53e1640400.js100ms93ms4ms1st
https://deepseek.com/_next/static/chunks/c56f180e-6001d5763de6082d.js79ms71ms7ms1st
B
Page Weight Inventory
24 resources · 1.0 MB · 308 KB savings available
REVIEW
24 resources · 1.0 MB · 308 KB savings available
Warning::
Page weight 46 KB over 1MB target
Got: 1.0 MB Expected: ≤ 1 MB
Info::
~308 KB of savings available
Warning::
7 third-party resources (52% of weight)
Info::
2 resources over 200KB
24 resources · 1.0 MiB · 7 third-party 46.5 KiB over 1MB target
JavaScript 69% · 734.2 KiB
Image 24% · 252.1 KiB
Font 4% · 47.7 KiB
Document 2% · 19.5 KiB
CSS 1% · 14.5 KiB
Other 0% · 2.5 KiB

~308.1 KiB of savings available

Remove unused JavaScript: 308.1 KiB
B
HTTP Caching
no-cache
REVIEW
no-cache
Info::
Cache-Control header is set
Got: no-cache
Info::
ETag present — enables conditional (304) responses
Info::
Last-Modified header present
Cache-Control

no-cache

DirectiveValueMeaning
no-cache—Cache but always revalidate first
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A
Image Optimization
2 images, 0 KB saveable
PASS
2 images, 0 KB saveable
Info::
All images are well-optimized
2 images 47 KB
0 oversized -0 KB
2 legacy format
0 missing dimensions CLS risk
A+
Font Loading
1 fonts (48 KB)
PASS
1 fonts (48 KB)
Info::
1 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

1

48 KB total

Render-blocking

0

of 1

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 1.1 s LCP 1.4 shttps://deepseek.com/_next/static/media/e4af272ccee01ff0-s.p.woff2e4af272ccee01ff0-s.p.woff2 https://deepseek.com/_next/static/media/e4af272ccee01ff0-s.p.woff2 — 47.7 KiB — 12 ms — font-display: swap
e4af272ccee01ff0-s.p.woff2 woff2 swap
Size 48 KB
Load time 12 ms
Start 672 ms
Risk FOUT — text flashes from fallback to web font
Optimization checklist
  • Preload critical fonts (priority=high)
  • Use woff2 format for all fonts
  • Set font-display to swap, optional, or fallback
  • Subset large fonts (≤100 KB each)
A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
24 requests over 1325ms
INFO
0 ms 500 ms 1.0 s FCP 1.1 s LCP 1.4 shttps://deepseek.com// https://deepseek.com/ — 202 — 2.5 KiB — 18 ms — h2https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/challenge.jsa0fea896111e.5368fe9c.eu-west-1.tok... https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/challenge.js — 200 — 502.1 KiB — 73 ms — h2https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/inputs?client=browsera0fea896111e.5368fe9c.eu-west-1.tok... https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/inputs?client=browser — 200 — 829 B — 79 ms — h3https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/mp_verifya0fea896111e.5368fe9c.eu-west-1.tok... https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/mp_verify — 200 — 616 B — 88 ms — h3https://deepseek.com/favicon.ico/favicon.ico https://deepseek.com/favicon.ico — 202 — 401 B — 6 ms — h2https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/mp_verifya0fea896111e.5368fe9c.eu-west-1.tok... https://a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com/a0fea896111e/3a8b889b892b/06b36ed26aca/mp_verify — 200 — 617 B — 58 ms — h3https://deepseek.com// https://deepseek.com/ — 200 — 16.6 KiB — 9 ms — h2https://deepseek.com/_next/static/media/e4af272ccee01ff0-s.p.woff2/_next/static/media/e4af272ccee01ff... https://deepseek.com/_next/static/media/e4af272ccee01ff0-s.p.woff2 — 200 — 47.7 KiB — 12 ms — h2https://deepseek.com/_next/static/css/4ed2fe305fed57cc.css/_next/static/css/4ed2fe305fed57cc.... https://deepseek.com/_next/static/css/4ed2fe305fed57cc.css — 200 — 8.0 KiB — 16 ms — h2https://deepseek.com/_next/static/css/b794593e5feb2b94.css/_next/static/css/b794593e5feb2b94.... https://deepseek.com/_next/static/css/b794593e5feb2b94.css — 200 — 4.5 KiB — 8 ms — h2https://deepseek.com/_next/static/css/2cbd522464c80da0.css/_next/static/css/2cbd522464c80da0.... https://deepseek.com/_next/static/css/2cbd522464c80da0.css — 200 — 2.0 KiB — 13 ms — h2https://deepseek.com/_next/static/chunks/webpack-2e06bec4baf15881.js/_next/static/chunks/webpack-2e06be... https://deepseek.com/_next/static/chunks/webpack-2e06bec4baf15881.js — 200 — 6.2 KiB — 6 ms — h2https://deepseek.com/_next/static/chunks/c56f180e-6001d5763de6082d.js/_next/static/chunks/c56f180e-6001d... https://deepseek.com/_next/static/chunks/c56f180e-6001d5763de6082d.js — 200 — 53.8 KiB — 39 ms — h2https://deepseek.com/_next/static/chunks/6714-6422be53e1640400.js/_next/static/chunks/6714-6422be53e... https://deepseek.com/_next/static/chunks/6714-6422be53e1640400.js — 200 — 29.2 KiB — 36 ms — h2https://deepseek.com/_next/static/chunks/main-app-0138e63140c237ca.js/_next/static/chunks/main-app-0138e... https://deepseek.com/_next/static/chunks/main-app-0138e63140c237ca.js — 200 — 818 B — 9 ms — h2https://deepseek.com/_next/static/chunks/8848-d252791ce07a3fe3.js/_next/static/chunks/8848-d252791ce... https://deepseek.com/_next/static/chunks/8848-d252791ce07a3fe3.js — 200 — 56.2 KiB — 28 ms — h2https://deepseek.com/_next/static/chunks/2278-6827556f92234ddf.js/_next/static/chunks/2278-6827556f9... https://deepseek.com/_next/static/chunks/2278-6827556f92234ddf.js — 200 — 30.4 KiB — 28 ms — h2https://deepseek.com/_next/static/chunks/app/%5Blocale%5D/layout-761353d13bda8476.js/_next/static/chunks/app/%5Blocale%... https://deepseek.com/_next/static/chunks/app/%5Blocale%5D/layout-761353d13bda8476.js — 200 — 2.2 KiB — 26 ms — h2https://deepseek.com/_next/static/chunks/5069-6affb9693b43a1d0.js/_next/static/chunks/5069-6affb9693... https://deepseek.com/_next/static/chunks/5069-6affb9693b43a1d0.js — 200 — 30.1 KiB — 38 ms — h2https://deepseek.com/_next/static/chunks/app/%5Blocale%5D/page-a8799f32b82d85c2.js/_next/static/chunks/app/%5Blocale%... https://deepseek.com/_next/static/chunks/app/%5Blocale%5D/page-a8799f32b82d85c2.js — 200 — 23.2 KiB — 35 ms — h2https://cdn.deepseek.com/blog/banner-background.webpcdn.deepseek.com/blog/banner-backgr... https://cdn.deepseek.com/blog/banner-background.webp — 200 — 37.4 KiB — 44 ms — h2https://cdn.deepseek.com/logo.png?x-image-process=image%2Fresize%2Cw_828cdn.deepseek.com/logo.png?x-image-p... https://cdn.deepseek.com/logo.png?x-image-process=image%2Fresize%2Cw_828 — 200 — 9.3 KiB — 7 ms — h2https://deepseek.com/favicon.ico/favicon.ico https://deepseek.com/favicon.ico — 200 — 205.4 KiB — 15 ms — h2https://chat.deepseek.com/api/v0/ip_to_country_codechat.deepseek.com/api/v0/ip_to_coun... https://chat.deepseek.com/api/v0/ip_to_country_code — 200 — 540 B — 287 ms — h2
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
54% of JavaScript execution is third-party
First-party Third-party 437ms · 502KB · $6/mo
a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com
Other
Costly
Execution 329ms
Transfer 502 KB
Unused 55%
Monthly Cost $4/mo
Unattributable
Other
Optional
Execution 109ms
Transfer 0 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com adds 329ms and costs ~$4/month

54% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com takes 329ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

55% of a0fea896111e.5368fe9c.eu-west-1.token.awswaf.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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