YouTube Engagement Heatmap
Explore when viewers commented on a public YouTube video: calendar, week × hour, first-48-hour and lifetime charts. Up to 5,000 recent top-level comments. Free, no login.
Find the conversations worth responding to
For your own channel, go beyond comment timing. A free comment audit highlights unanswered questions, viewer feedback, and moderation risks in a recent sample.
The audit is free and needs no login. Connect your channel only when you want to act.
What this engagement heatmap tells you
Explore when people commented on a public YouTube video. The calendar, week × hour grid, first-48-hour chart and lifetime timeline describe up to 5,000 recent public top-level comments in your local timezone.
These are comment timestamps, not viewing times, audience availability, or evidence of what caused a video to grow. On a busy video, older comments may fall outside the sample.
How to use the engagement heatmap
- Copy a public YouTube video URL from its address bar or Share menu.
- Paste it into the input above to load the charts.
- Check the sample size and date coverage before interpreting early or lifetime activity.
- Explore the calendar and week × hour grid. Click a populated cell to read its comments.
- Compare the first 48 hours with later activity only when the sample covers those periods.
- Use each chart’s Embed button or share the page URL to show the same video.
Four views of comment activity
- Calendar heatmap: comments per day, with the upload date marked.
- Week × hour grid: the days and hours with the most comments in the sample.
- First 48 hours: sampled comments posted shortly after publication. A recent sample may omit this period.
- Lifetime timeline: comment activity across the dates represented in the sample, with optional time filters.
Can comment timing help you choose when to post?
It can give you a starting question to investigate, but people commenting on one video are not a representative measure of when your whole audience is online. Topic, promotion, publication time and the sample’s date range can all affect the pattern.
For your own channel, compare the pattern with YouTube Studio’s audience report. YouTube says publish time is not known to affect long-term video performance. Use the heatmap to explore activity, not to promise a better ranking or a guaranteed upload schedule.
Reading the first 48 hours after publication
When early comments are included, the chart shows how comment activity changed hour by hour. It does not reveal recommendation decisions, impressions, watch time or why people arrived.
If the tool’s recent-comment limit excludes the launch period, a quiet chart is missing evidence, not a failed launch. Check coverage before comparing videos.
Understanding later comment activity
Later comments can help you spot questions on older videos that still need a response. A spike is a reason to read the thread and investigate traffic sources; it does not establish external promotion, coordinated activity or revenue.
For creators, marketers and researchers
Creators can find busy discussion periods and return to comments on older uploads. Community teams can inspect the comments behind a spike. Researchers can describe the observed pattern while reporting the sampling cap and date coverage.
For questions about buying, sponsorships or recurring viewer requests, try the channel comment audit. To keep the sampled text for analysis, use the comment exporter.
How the data is collected
CommentShark uses the YouTube Data API to retrieve up to 5,000 recent public top-level comments. This cap belongs to this tool. Each comment’s publishedAt timestamp is grouped by day and hour in your browser’s timezone.
Deleted, private and held comments are not included. Missing comments and truncated history limit what the charts can tell you. Comments measure participation, not views or earnings.
Frequently asked questions
What is the best time to post on YouTube?
This tool shows when the sampled comments were posted, not when all your viewers are online. Use YouTube Studio’s audience report to inform scheduling. YouTube says publish time is not known to affect a video’s long-term performance. Comment timing can suggest questions to investigate, but cannot establish an ideal upload time.
What is a YouTube comment heatmap?
It groups the sampled public comments by date and hour. Darker cells mean more comments in that time bucket. Calendar, weekly, first-48-hour and lifetime views show different parts of the same sample.
How do I see when comments were posted on a YouTube video?
Paste a public video URL into the tool. It reads comment timestamps through the YouTube Data API and groups them in your browser’s local timezone.
Does the heatmap include every comment?
CommentShark samples up to 5,000 recent public top-level comments per video. This is the tool’s limit, not a limit on the YouTube API’s full history. Deleted, private and held comments are absent. On a busy video, the sample may not reach back to publication, so missing early activity does not mean nobody commented then.
Why did a video get a spike in comments?
The chart shows when activity increased, but cannot tell you why. Read the comments and, for your own channel, compare YouTube Studio traffic-source and audience reports. A spike alone does not prove a recommendation boost, coordinated campaign or external promotion.
Is this YouTube engagement heatmap free?
Yes. No account is needed to analyze a public video. CommentShark fetches the sample through the YouTube Data API; the charts render in your browser.
Can I embed the engagement charts on my own website?
Yes. Each chart’s Embed button provides an iframe snippet for a standalone chart with CommentShark attribution. You can also share the page URL for the loaded video.
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