Compress Video for an Online Course: Teachable, Kajabi, Udemy

Teachable recommends 2 GB per video and accepts uploads up to 20 GB; Kajabi caps a video upload at 4 GB. Both pages name MP4, so that is the safe container for every lesson.

Two details matter. Teachable also says larger video files may take several minutes to upload and optimize, and in its course setup guide suggests compressing large videos with a tool like Handbrake. And Kajabi’s own example of a 16:9 ratio lists portrait pixel dimensions, so ignore that example and keep the frame landscape.

What does that mean in minutes of video?

The math: 4 GB at 10,000 kbps lasts about 53 minutes (3,200 seconds), and at 5,000 kbps about 107 minutes. Teachable’s 2 GB at 5,000 kbps is about 53 minutes. These are video-stream estimates in decimal gigabytes, so leave 5% of margin for audio and container overhead.

Check Udemy’s own instructor help center for its current video requirements before you export. This page does not quote Udemy figures, so you always see the live ones. For the other end of the pipeline, see our guide for teachers and schools uploading to an LMS.

What carries over from the two platforms above is the export itself: a 16:9 landscape frame at 1080p, an MP4 container, H.264 video, AAC audio with the voice track present, and a file you have checked for size before you upload. If you sell the same course on Udemy and on Teachable or Kajabi, one export at those settings is the place to start, then compare it with each platform’s page.

Use 1080p (1920 × 1080) for lessons that show a face, slides or a screen. Teachable recommends it, Kajabi treats it as the upload maximum, and anything higher raises file size without adding legibility on the laptop and phone screens students use.

Screen recordings are the exception that needs care. A 14-inch MacBook Pro records at 3024 × 1964, which is about 2.86 times the pixels of a 1080p frame. In our screen recording test, a 60-second capture of 56,384,195 bytes came out at 3,691,160 bytes with Smol’s default (H.265, high; 93.5% smaller) and 1,399,221 bytes with Resolution 1920 (97.5% smaller, 1662 × 1080, same codec). That is one recording of one screen; text-heavy software demos and slide decks will differ, so check a result for legibility before you batch the module.

• Keep the aspect ratio 16:9. Kajabi names 16:9, and Teachable’s 1920 × 1080 is the same shape.
• Do not upscale. A 720p recording blown up to 1080p adds bytes, not detail.
• Record at the size you will publish when you can. Downscaling later works, but a 1080p capture skips the step.

Set MP4 and H.264, reduce the resolution to 1080p if the source is larger, and pick High or Web quality. Smol’s High label is CRF 24 and Web is CRF 28; lower CRF means higher quality and a larger file.

Smol’s video default is H.265, which makes smaller files, but H.264 is the safer pick for a course host. Neither Teachable nor Kajabi names a codec on the pages above, and on caniuse data as of 27 September 2026, H.264 had full support in 97.26% of global browser usage against 16.94% for HEVC. If your host says it takes H.265, the smaller files are worth it; see H.265 vs H.264.

For scale, from our batch video test: twelve 5-second 1080p clips (about 18 Mbps H.264 sources) went from 135,034,271 bytes to 14,005,659 with Smol pinned to H.265 at CRF 28, an 89.6% reduction. Course footage is longer and quieter, so your savings will differ.

Compress by module, not by file. Drop a folder of lesson exports into Smol and it writes a copy of each with a _compressed suffix next to the original, which by default is left untouched.

1. 1

   Export lessons from your editor at 1080p

   Use the highest quality your editor offers; Smol does the shrinking. Our video delivery guide covers export for teams.

2. 2

   Drop the module folder into Smol

   Mixed batches are fine, so workbook PDFs and audio files can ride along with the video.

3. 3

   Set MP4, H.264, 1080p and the quality from the table

   Start with High (CRF 24) for camera lessons and Web (CRF 28) for slides, and keep audio on.

4. 4

   Run it and sort the outputs by size

   Find the largest file. If it clears your host’s cap and bitrate, the rest do too.

5. 5

   Watch one lesson through before uploading

   Check that small on-screen text reads and the voice track is intact.

6. 6

   Save the settings as a preset

   Presets live on that Mac. On a second computer, write the settings down and recreate them.

The comparison between these is in HandBrake alternatives for Mac and how to compress a video on Mac. Source clip: 30,704,510 bytes, 1080p, 10 seconds.

• You need a hard byte target. Smol sets quality and resolution, not output size, and has no size target for video. A tool with a bitrate target does.
• You edit, caption or trim. Smol does not cut footage, add captions or fix audio levels. Finish the edit first.
• You are not on a Mac. Smol runs on macOS only.
• You need a master copy. Smol re-encodes to make files smaller, so keep your original export as the master.
• Your host transcodes anyway and has no tight cap. If every file is well under the limit, skip the extra step.

For a team shipping a course to several hosts, read the pricing page: Solo is $29 for one Mac, Team is $49 for three Macs.