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JavaScript

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fetchLater() API API

AbortController

640KiB

fetchLater() JavaScript QuotaExceededError

RUM deferred-fetch deferred-fetch-minimal

fetchLater() 640KiB 512KiB 128KiB

• 512KiB fetchLater()
• 128KiB <iframe><object><embed> <frame> fetchLater()

fetchLater() URL

a.com <script> analytics.example.com fetchLater() 512KiB analytics.example.com fetchLater() <iframe> 128KiB

512KiB URL 64KiB

128KiB 8KiB DOM fetchLater() 16 fetchLater() 16 128KiB

64KiB 512KiB DOM 64KiB

deferred-fetch-minimal 128KiB deferred-fetch-minimal () 128KiB deferred-fetch 640KiB

fetchLater() 64KiB deferred-fetch 64KiB fetchLater() 8KiB deferred-fetch Permissions-Policy

fetchLater() QuotaExceededError

fetchLater() QuotaExceededError

fetchLater() JavaScript QuotaExceededError

Permissions-Policy: deferred-fetch=(self "https://b.com")

1. <iframe src="https://b.com/page"> 512KiB 64KiB
2. <iframe src="https://c.com/page"> 128KiB 8KiB
3. 15 iframe 8KiB c.com
4. iframe
5. iframe
6. iframe 8KiB

Permissions-Policy: deferred-fetch-minimal=("https://b.com")

1. <iframe src="https://b.com/page"> 8KiB
2. <iframe src="https://c.com/page">
3. 512KiB

Permissions-Policy: deferred-fetch=(self "https://b.com")
Permissions-Policy: deferred-fetch-minimal=()

1. <iframe src="https://b.com/page"> 64KiB
2. <iframe src="https://c.com/page">
3. 640KiB b.com 574KiB b.com 64KiB

Permissions-Policy: deferred-fetch-minimal=()

1. 640KiB
2. fetchLater()

a.com a.com b.com

1. a.com 512KiB
2. <iframe src="https://a.com/embed"> 512KiB
3. <iframe src="https://b.com/embed"> 8KiB

a.com <iframe src="https://b.com/"> <iframe src="https://a.com/embed">

1. a.com 512KiB
2. <iframe src="https://b.com/"> 8KiB
3. <iframe src="https://a.com/embed">

a.com <iframe src="https://b.com/"> <iframe src="https://c.com/">

1. a.com 512KiB
2. <iframe src="https://b.com/"> 8KiB
3. <iframe src="https://c.com/">

a.com <iframe src="https://b.com/"> <iframe src="https://c.com/">

a.com

Permissions-Policy: deferred-fetch=("https://c.com" "https://c.com")

b.com

Permissions-Policy: deferred-fetch=("https://c.com")

1. a.com 512KiB
2. <iframe src="https://b.com/"> 64KiB
3. <iframe src="https://b.com/"> 8KiB c.com b.com fetchLater()
4. <iframe src="https://c.com/"> 8KiB

a.com <iframe src="https://b.com/"> c.com

1. a.com 512KiB
2. <iframe src="https://b.com/"> 8KiB
3. <iframe src="https://b.com/"> c.com 8KiB c.com

iframe

<iframe> https://www.example.com

<iframe src="https://www.example.com/iframe" sandbox="allow-scripts"></iframe>

<iframe> 128KiB 8KiB

iframe fetchLater()

<iframe> fetchLater() <iframe> allow

<iframe
  src="https://www.example.com/iframe"
  allow="deferred-fetch;deferred-fetch-minimal;"></iframe>

iframe 512KiB allow=deferred-fetch iframe 128KiB allow="deferred-fetch-minimal" src

QuotaExceededError

//  64KiB
const url = "<72KiB of characters>";
fetchLater(url);

//  64KiB
fetchLater("https://origin.example.com", { headers: headersExceeding64KiB });

//  64KiB
fetchLater("<32KiB of characters>", { headers: headersExceeding32KiB });

//  64KiB
fetchLater("https://origin.example.com", {
  method: "POST",
  body: bodyExceeding64KiB,
});

//  64KiB
fetchLater("<62KiB of characters>" /* 3kb  */);

QuotaExceededError

2 3 640KiB 3 https://a.example.com

fetchLater("https://a.example.com", { method: "POST", body: a40KiBBody });
fetchLater("https://b.example.com", { method: "POST", body: a40KiBBody });
fetchLater("https://a.example.com", { method: "POST", body: a40KiBBody });

a.com <iframe src="https://b.com/"> a.com

1. a.com 512KiB
2. <iframe src="https://b.com/"> 128KiB 8KiB
3. <iframe src="https://b.com/"> a.com 8KiB a.com a.com 8KiB