Compress Video for YouTube Upload: Bitrate, Codec and Size

YouTube’s maximum upload is 256 GB or 12 hours, whichever is less. By default, YouTube uploads are limited to 15 minutes. YouTube also publishes bitrates for the best result, shown below by resolution and frame rate.

Figures were read on YouTube Help on 11 October 2026. YouTube’s recommended container is MP4 with the moov atom at the front of the file (called Fast Start), H.264 High Profile, 4:2:0 chroma, and AAC-LC or Opus audio at 48 kHz. These are recommendations, not a ceiling. A higher bitrate means a larger file and a longer upload.

Start with YouTube’s own table: 8 Mbps for 1080p at standard frame rates, 12 Mbps at 48 to 60 fps, 16 Mbps for 1440p and 35 to 45 Mbps for 4K. Going lower saves upload time but costs detail in fast motion. Going higher costs time and gains little.

Smol does not take a bitrate. It takes a quality, either a label (High is CRF 24, Web is CRF 28) or an exact CRF from 0 to 63, so the bitrate it produces depends on the footage. In the compress-video test, a 10-second 1080p animated clip went from 30,704,510 bytes to 6,111,954 at High with H.265, 80.1% smaller. That is about 4.9 Mbps, under YouTube’s 8 Mbps line, on one easy clip. Busy footage (handheld, foliage, confetti) needs a lower CRF number to hold detail. Treat 24 as a starting point, then watch a fast section of the output before you upload.

Usually the file is bigger than it needs to be and your upload speed is the bottleneck. Upload time is the file size in megabits divided by your upload speed, so halving the file halves the wait, whatever the platform does.

That table is plain arithmetic (size times 8 divided by link speed), not a YouTube measurement. Real uploads add protocol overhead and wobble with your connection. Check your own upload speed, which is usually far lower than the download speed on a home plan. If the number is small, compressing is the one lever you control. The guide to reducing video file size covers the same levers for other destinations.

Yes, YouTube lists HEVC (H.265) among its supported file formats, next to .MOV, .MP4, WebM, ProRes, DNxHR and CineForm. Its recommended settings, though, name H.264. H.265 can make a smaller file for similar quality, which helps the upload, though on calm footage the saving can be small.

Pick by risk. If the upload must work first time on a deadline, use H.264 in an MP4, the combination YouTube recommends. If you are uploading long, large videos and the file is the problem, an H.265 upload cuts the bytes and YouTube lists it as supported. Smol’s video default is H.265, and one switch makes it H.264. After either, play the finished file in QuickTime Player and check the processed result on YouTube before you publish. H.265 versus H.264 explains what changes.

Use Compress, not Convert, so your quality setting applies. These are starting points, not measured thresholds: Smol sets quality and resolution, not output bytes, so check the file size each time.

Smol also offers nine speed presets and an exact CRF from 0 to 63. The tested numbers are in compressing 4K video on a Mac.

1. 1

   Export your best master from the editor

   Export once at the resolution and frame rate you want to publish. Compress this file, not a copy of a copy.

2. 2

   Drop it into Smol

   Drag in one video or the whole folder. Mixed batches are fine. Smol writes a _compressed copy beside the original, so the master is untouched by default.

3. 3

   Choose MP4 and a codec

   H.264 matches YouTube’s recommended settings. H.265 gives the smaller file.

4. 4

   Set quality and keep the resolution

   Start at High (CRF 24). Keep the resolution unless this is a draft.

5. 5

   Check the size and a busy section

   Read the output size, then scrub through the fastest section. If detail smears, lower the CRF number and run it again. If the file is still huge, raise it.

6. 6

   Upload the compressed copy

   In YouTube Studio, upload the _compressed file and wait for processing to finish before you publish.

For a backlog, batch compress videos in one drop.

If you already export at 8 Mbps from your editor, you may not need anything else. Smol earns its place when you export at a high bitrate to be safe and want a fast, repeatable shrink afterwards. See the HandBrake comparison for the tradeoffs.

• You need a specific bitrate in Mbps. Smol takes CRF and quality labels, so use an editor export or a two-pass tool for exact bitrates.
• You must hit a byte count. Video has no size-target mode in Smol; the output size has to be checked.
• You want to edit, trim, add captions or color grade. Smol compresses the finished file and does none of those.
• You are on Windows or Linux. Smol is macOS only.
• You publish on a deadline with HDR masters. Test one export through YouTube before you commit a whole batch.

Thumbnails are a separate job; see YouTube thumbnails. For delivering finished work to a client, see video delivery.