Performance
· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
1.19 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.58 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.36 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.017
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
4.78 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.
7.58 s
Page Load Progression
FPage Weight BudgetAction6.1 MB transferred, 227 requestsFIX
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
Subset fonts to include only used characters, or switch to system font stacks.
Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).
Source: web.dev font loading
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction6730ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.ted.com/_next/static/chunks/10ve7kro4jeja.js | 1152ms | 913ms | 7ms | 3rd |
| https://www.ted.com/ | 972ms | 14ms | 3ms | 3rd |
| https://www.ted.com/_next/static/chunks/13mh4qsg0ojc3.js | 858ms | 69ms | 4ms | 3rd |
| https://www.ted.com/_next/static/chunks/0.jna.w-3mqdg.js | 641ms | 443ms | 0ms | 3rd |
| Unattributable | 575ms | 73ms | 0ms | 3rd |
| https://www.ted.com/_next/static/chunks/0-1uuud_vkogc.js | 313ms | 39ms | 5ms | 3rd |
| https://cmp.osano.com/AzqTgHUHUGJa7gInt/9e4d9097-fa02-474b-9ac9-958cf3f54337/osano.js | 307ms | 264ms | 10ms | 3rd |
| https://www.ted.com/_next/static/chunks/turbopack-0li4q.l8idl5g.js | 252ms | 250ms | 1ms | 3rd |
| https://www.ted.com/_next/static/chunks/turbopack-0azua~rknfwv~.js | 210ms | 198ms | 1ms | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604130101/pubads_impl.js | 207ms | 152ms | 23ms | 3rd |
Showing top 10 of 22 scripts
FJS BundlesAction112 scripts, 1.0 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://static.fundraiseup.com/checkout.2fb913ca26161876.js | 403 KB | 359 KB (89%) | ✓ | 3rd |
| https://cdn.yourbow.com/ted/hbyb.js | 196 KB | 145 KB (74%) | ✓ | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604130101/pubads_impl.js | 188 KB | 129 KB (69%) | ✓ | 3rd |
| https://static.fundraiseup.com/checkout-sentry-vendor.dda4c7629502a974.js | 112 KB | 112 KB (100%) | ✓ | 3rd |
| https://static.fundraiseup.com/checkout-vendors.78ab7844d94042df.js | 105 KB | 87 KB (83%) | ✓ | 3rd |
| https://www.ted.com/_next/static/chunks/0ohty3wb33a.t.js | 84 KB | 62 KB (74%) | ✓ | 3rd |
| https://www.ted.com/_next/static/chunks/0bmiy_96-93.m.js | 71 KB | 45 KB (64%) | ✓ | 3rd |
| https://www.ted.com/_next/static/chunks/0x.hrftbimb3a.js | 35 KB | 35 KB (100%) | ✓ | 3rd |
| https://www.ted.com/_next/static/chunks/092zji5u07qgk.js | 52 KB | 33 KB (62%) | ✓ | 3rd |
| https://static.fundraiseup.com/checkout-styles.8d2f5640734b6a7c.js | 22 KB | 22 KB (100%) | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
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.
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.
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.
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.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
FPage Weight InventoryAction227 resources · 6.1 MB · 1.0 MB savings availableFIX
~1.0 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 227 resources | 6.1 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization31 images, 0 KB saveableREVIEW
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font Loading2 fonts (363 KB)PASS
Web fonts
2
363 KB total
Render-blocking
0
of 2
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Convert to woff2 for ~30% smaller file size
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)
Fixing the unchecked items could save ~178 KB and ~356 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall227 requests over 7754msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.ted.com www.ted.com | Other | 1152ms | 60 KB | — | €13/mo | Costly |
www.ted.com www.ted.com | Other | 972ms | 58 KB | — | €11/mo | Costly |
www.ted.com www.ted.com | Other | 858ms | 22 KB | — | €9/mo | Costly |
www.ted.com www.ted.com | Other | 641ms | 0 KB | — | €7/mo | Costly |
Unattributable Unattributable | Other | 575ms | 0 KB | — | €6/mo | Costly |
www.ted.com www.ted.com | Other | 313ms | 43 KB | 51% | €3/mo | Costly |
cmp.osano.com cmp.osano.com | Other | 307ms | 55 KB | — | €3/mo | Costly |
www.ted.com www.ted.com | Other | 252ms | 4 KB | — | €3/mo | Costly |
www.ted.com www.ted.com | Other | 210ms | 4 KB | — | €2/mo | Costly |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 207ms | 188 KB | 69% | €2/mo | Costly |
cdn.yourbow.com cdn.yourbow.com | Other | 184ms | 196 KB | 74% | €2/mo | Optional |
cdn.fundraiseup.com cdn.fundraiseup.com | Other | 134ms | 65 KB | 34% | €1/mo | Optional |
static.fundraiseup.com static.fundraiseup.com | Other | 127ms | 105 KB | 83% | €1/mo | Optional |
www.ted.com www.ted.com | Other | 126ms | 23 KB | — | €1/mo | Optional |
static.cdn.prismic.io static.cdn.prismic.io | Other | 117ms | 10 KB | — | €1/mo | Optional |
www.ted.com www.ted.com | Other | 113ms | 2 KB | — | €1/mo | Optional |
www.ted.com www.ted.com | Other | 79ms | 71 KB | 64% | €1/mo | Optional |
www.ted.com www.ted.com | Other | 77ms | 15 KB | — | €1/mo | Optional |
b-code.liadm.com b-code.liadm.com | Other | 75ms | 47 KB | — | €1/mo | Optional |
static.fundraiseup.com static.fundraiseup.com | Other | 73ms | 403 KB | 89% | €1/mo | Optional |
www.ted.com www.ted.com | Other | 72ms | 3 KB | — | €1/mo | Optional |
ak.sail-horizon.com ak.sail-horizon.com | Other | 65ms | 48 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- www.ted.com adds 1152ms and costs ~€13/month
- www.ted.com adds 972ms and costs ~€11/month
- www.ted.com adds 858ms and costs ~€9/month
- www.ted.com adds 641ms and costs ~€7/month
- Unattributable adds 575ms and costs ~€6/month
- www.ted.com adds 313ms and costs ~€3/month
- cmp.osano.com adds 307ms and costs ~€3/month
- www.ted.com adds 252ms and costs ~€3/month
- www.ted.com adds 210ms and costs ~€2/month
- securepubads.g.doubleclick.net adds 207ms and costs ~€2/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.
Learn more ▾ ▴
Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.
Source: web.dev
www.ted.com takes 1152ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.ted.com takes 972ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.ted.com takes 858ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.ted.com takes 641ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Unattributable takes 575ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.ted.com takes 313ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
51% of www.ted.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
cmp.osano.com takes 307ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.ted.com takes 252ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.ted.com takes 210ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
securepubads.g.doubleclick.net takes 207ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
69% of securepubads.g.doubleclick.net's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
74% of cdn.yourbow.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
83% of static.fundraiseup.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
64% of www.ted.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
89% of static.fundraiseup.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev