Playlist · Cognito
GCSE Biology (9-1)
Listed in Best free GCSE and A-level revision courses on YouTube, ranked by total hours
Total watch time
8h 24m
at 1× speed · exactly 8 hours, 24 minutes, 13 seconds at 1×
At an hour a day you'd finish in 9 days
The shape of the course
94 videos in blocks of 10 · each column is a block's total, to scale
WatchedTo watch
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Your plan
Plan to finish
About 9 days at an hour a day
Pick a daily pace and the days you'll watch. Ticked videos are skipped.
At one hour a day, every day, this playlist takes about 9 days. Turn on JavaScript to plan around your week.
How do I import this?
Google Calendar: in the left sidebar, + beside Other calendars → Import → pick the downloaded .ics → choose a calendar → Import. The same menu's From URL subscribes to the feed instead.
Apple Calendar (Mac): double-click the file or drag it onto Calendar → choose a calendar → Add all.
iPhone / iPad: open the file from Files, Mail or Safari's download bar → Add All → choose a calendar.
Outlook, Android, and subscribing instead of importing: step by step for every app →
Videos (94)
8h 24m in total · tick what you've watched
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For your README
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Show the watch time in a README or course description — it links back here and updates itself
[](https://playlistduration.com/playlist/PLidqqIGKox7X5UFT-expKIuR-i-BN3Q1g)<a href="https://playlistduration.com/playlist/PLidqqIGKox7X5UFT-expKIuR-i-BN3Q1g"><img src="https://playlistduration.com/badge/playlist/PLidqqIGKox7X5UFT-expKIuR-i-BN3Q1g.svg" alt="Watch time: 8h 24m · 94 videos" width="203" height="20"></a>Add ?speed=1.5 to the image URL for the time at that speed, ?label=Course to change the left text, or ?style=flat-square for square corners.
Want the numbers themselves? GET https://playlistduration.com/api/v1/playlist/PLidqqIGKox7X5UFT-expKIuR-i-BN3Q1g returns them as JSON — free, no key. API docs →
Data from the YouTube Data API as of 2026-10-21 (cached). Private or deleted videos are excluded from totals.