Get YouTube video retention curve
Returns the audience retention curve for a single YouTube video, plus the video's duration for rendering the curve on a time axis. The curve has up to 100 points (elapsedVideoTimeRatio 0.01-1.0) aggregated over the whole date range; YouTube does not support per-day retention breakdowns.
audienceWatchRatio is the absolute share of viewers watching at that point in the video and can exceed 1 (rewinds and looping, common on Shorts). relativeRetentionPerformance compares against videos of similar length (0 = worst, 0.5 = median, 1 = best). YouTube returns an empty curve for videos with very few views or before analytics processing completes (2-3 day delay).
Requires yt-analytics.readonly scope (re-authorization may be needed).
Authorization
bearerAuth API key authentication: send your Zernio API key in the Authorization header, prefixed with Bearer.
In: header
Query Parameters
The YouTube video ID (e.g., "dQw4w9WgXcQ")
The Zernio account ID for the YouTube account
Start date (YYYY-MM-DD). Defaults to the video's publish date (lifetime curve).
dateEnd date (YYYY-MM-DD). Defaults to 3 days ago, the newest fully finalized day (YouTube finalizes analytics with a ~3-day delay). An explicit endDate is honored up to today: days inside the delay window are provisional and may still be revised by YouTube (see provisionalSince in the response).
dateResponse Body
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{ "success": true, "accountId": "65f1a2b3c4d5e6f7a8b9c0d1", "videoId": "zF7Gp4jnDa0", "title": "what's your choice?", "publishedAt": "2026-05-20T12:00:00Z", "durationSeconds": 24, "dateRange": { "startDate": "2026-05-20", "endDate": "2026-06-09" }, "retentionCurve": [ { "elapsedVideoTimeRatio": 0.01, "audienceWatchRatio": 1.6956, "relativeRetentionPerformance": 0.73665, "startedWatching": 280331, "stoppedWatching": 5348, "totalSegmentImpressions": 478466 }, { "elapsedVideoTimeRatio": 0.02, "audienceWatchRatio": 1.678, "relativeRetentionPerformance": 0.73865, "startedWatching": 385, "stoppedWatching": 11790, "totalSegmentImpressions": 473492 } ], "scopeStatus": { "hasAnalyticsScope": true }}Get YouTube daily views
Returns daily view counts for a YouTube video including views, watch time, and subscriber changes. Requires yt-analytics.readonly scope (re-authorization may be needed). YouTube finalizes analytics with a ~3-day delay; by default only finalized days are returned, and an explicit endDate can reach into the delay window (see the endDate parameter). Max 90 days, defaults to last 30 days.
Get YouTube demographics
Returns audience demographic insights for a YouTube channel, broken down by age, gender, and/or country. Pass videoId to get the audience profile of a single video instead of the whole channel. Age and gender values are viewer percentages (0-100). Country values are view counts. Data is based on signed-in viewers only, with a 2-3 day delay. YouTube suppresses demographics for videos with too few signed-in views, so low-traffic videos can return empty breakdowns. Requires the Analytics add-on.