The number of reported reasons a page was not restored from the back/forward cache on a back/forward navigation. 0 when the browser reported no reasons (e.g. non-Chromium browsers).
{
"key": "browser.bfcache.not_restored_reason_count",
"brief": "The number of reported reasons a page was not restored from the back/forward cache on a back/forward navigation. 0 when the browser reported no reasons (e.g. non-Chromium browsers).",
"type": "integer",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"examples": [
2
],
"changelog": [
{
"version": "0.19.0",
"prs": [
513
],
"description": "Added browser.bfcache.not_restored_reason_count attribute"
}
]
}
Whether a back/forward navigation was restored from the browser's back/forward cache (bfcache). 'hit' means the page was restored; 'miss' means it was reloaded.
A browser-reported reason a page was not restored from the back/forward cache on a back/forward navigation, taken from the notRestoredReasons API. Reported per reason (a single miss can have several). Currently Chromium-only.
{
"key": "browser.bfcache.reason",
"brief": "A browser-reported reason a page was not restored from the back/forward cache on a back/forward navigation, taken from the notRestoredReasons API. Reported per reason (a single miss can have several). Currently Chromium-only.",
"type": "string",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"examples": [
"unload-listener",
"websocket",
"idbversionchangeevent",
"response-cache-control-no-store"
],
"changelog": [
{
"version": "0.19.0",
"prs": [
513
],
"description": "Added browser.bfcache.reason attribute"
}
]
}
{
"key": "browser.web_vital.fcp.value",
"brief": "The time it takes for the browser to render the first piece of meaningful content on the screen",
"type": "double",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"example": 547.6951,
"alias": [
"fcp"
],
"changelog": [
{
"version": "0.5.0",
"prs": [
235
]
}
]
}
{
"key": "browser.web_vital.fp.value",
"brief": "The time in milliseconds it takes for the browser to render the first pixel on the screen",
"type": "double",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"example": 477.1926,
"alias": [
"fp"
],
"changelog": [
{
"version": "0.5.0",
"prs": [
235
]
}
]
}
{
"key": "browser.web_vital.lcp.id",
"brief": "The id of the dom element responsible for the largest contentful paint",
"type": "string",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"example": "#gero",
"alias": [
"lcp.id"
],
"changelog": [
{
"version": "0.5.0",
"prs": [
233
]
}
]
}
{
"key": "browser.web_vital.lcp.load_time",
"brief": "The time it took for the LCP element to be loaded",
"type": "integer",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"example": 1402,
"alias": [
"lcp.loadTime"
],
"changelog": [
{
"version": "0.5.0",
"prs": [
233
]
}
]
}
{
"key": "browser.web_vital.lcp.render_time",
"brief": "The time it took for the LCP element to be rendered",
"type": "integer",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"example": 1685,
"alias": [
"lcp.renderTime"
],
"changelog": [
{
"version": "0.5.0",
"prs": [
233
]
}
]
}
{
"key": "browser.web_vital.ttfb.request_time",
"brief": "The time it takes for the server to process the initial request and send the first byte of a response to the user's browser",
"type": "double",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"example": 1554.5814,
"alias": [
"ttfb.requestTime"
],
"changelog": [
{
"version": "0.5.0",
"prs": [
235
]
}
]
}
{
"key": "browser.web_vital.ttfb.value",
"brief": "The value of the recorded Time To First Byte (TTFB) web vital in Milliseconds",
"type": "double",
"apply_scrubbing": {
"key": "manual"
},
"is_in_otel": false,
"visibility": "public",
"example": 194.3322,
"alias": [
"ttfb"
],
"changelog": [
{
"version": "0.5.0",
"prs": [
235
]
}
]
}