Webinar Recording File Size: Limits and How to Shrink a Replay

Size is bitrate times seconds, divided by 8. A one-hour webinar at 6,000 kbps is 2.7 GB, at 8,000 kbps it is 3.6 GB, and at 15,000 kbps it is 6.75 GB.

Those bitrates are not arbitrary. Wistia recommends 5,000 to 8,000 kbps for an export, says most uploads fall in the 6,000 to 8,000 kbps range, and tells you to go no higher than 15,000 kbps (Wistia). It also says that a file under 2 hours long and larger than 8 GB probably means a compression step was missed. Divide your own file size by its minutes and multiply by 60 to learn what your platform writes. A slide-and-voice webinar has less motion than a camera-heavy one, so it often has more room to shrink.

For a budget, work backward. A 1 GB cap over 60 minutes leaves about 2,222 kbps of total bitrate, video and audio together. The same sum for a 15 MB clip of one minute gives 2,000 kbps. The email video guide explains why to aim at 15 MB for a 25 MB cap.

A GoToWebinar recording has no fixed size, so measure a real recording from your account and use the arithmetic above.

What changes the number is the same on every platform: resolution, bitrate, whether a webcam is recorded, and how long the session ran. If the file you downloaded is too big for where it has to go, the fix is the same too. Re-encode it as an H.264 MP4 and check the result. The same reasoning applies to a recording from any other webinar tool. Meeting-style calls have their own page, Zoom recordings.

For the hosts below, the file-size cap is rarely the problem; the practical limit is the email or chat step in front of it. The table lists each limit with its source.

Check your own plan too. Your video platform may set stricter rules than its help page, and your learning system or membership site has its own. The online course creators page covers replays that end up in a paid course.

Lower the resolution first, then raise the compression. Text on slides stays readable at 1280 or 1920 pixels wide, and the quality label does the rest. These are starting points we chose, so check the result.

H.265 can give a smaller file (3% to 30% in our test, depending on footage), but H.264 plays on more devices, and Wistia requires H.264/AVC, so use H.264 for any host you do not control. The H.265 vs H.264 post shows the trade-off with measured figures. In Smol, High is CRF 24 and Web is CRF 28, and you can type any CRF from 0 to 63. Smol sets quality and resolution, not output bytes, so open the result and compare it with your cap before you upload. For audio settings, see how to compress an audio file.

Trim the recording, drop it into Smol, choose the settings above, and upload the compressed copy. Smol writes _compressed beside the original and does not overwrite it by default.

1. 1

   Trim the dead air

   Cut the waiting room and the post-Q&A minutes in your editor first. Fewer minutes means fewer bytes at any setting. Smol compresses; it does not edit.

2. 2

   Drag the file or the folder into Smol

   A whole folder works, so a season of webinars goes in as one batch.

3. 3

   Set the output

   MP4 with H.264 for a host you do not control, High for a replay page, Web for chat. Lower the resolution for slide-heavy sessions.

4. 4

   Run it and read the size

   Smol shows per-file savings when it finishes. If it is over your cap, lower the resolution again and re-run.

5. 5

   Upload the compressed copy

   Keep the original until the replay plays correctly on the host.

Free tools come first, and for one recording a year they are enough. The table compares them fairly.

If you run webinars every week, a queue that handles a folder at once saves the repeating. Our HandBrake comparison and compress a video on Mac walk through the options, and batch compressing videos covers the folder case. A produced replay for sale belongs on the video production page.

Smol is the wrong tool in a few cases, and it is better to know now.

• You need captions or a transcript. Smol does not transcribe or caption.
• You need to cut, merge or add a title card. Smol compresses; it does not edit video.
• Your platform hosts and streams the replay for you and you only share its link. Nothing needs compressing.
• You are on Windows or Linux. Smol runs on macOS only.
• You must hit an exact byte cap with no checking. Smol sets quality and resolution, so you check the result.

Do teams need more than one license?

Solo is $29 for one Mac. Team is $49 for three Macs, and Enterprise is $20 a seat for 5 to 500 seats. Settings are saved in the app on each Mac, so a marketing team writes its video settings down and recreates them on every machine. See the pricing page.