File-size problems
Video file too large to upload? Shrink it with the right settings
Short answer
A file is too large when it is over the platform's limit: X allows 512 MB for non-Premium accounts, LinkedIn 5 GB. Pinterest's video ad spec lists 2 GB, while its organic Pin spec states no video size. Cut the size with a higher CRF in H.264, a lower resolution only if you must, and a normal audio bitrate. An increase of 6 in x264's CRF roughly halves the file size, so try CRF 23 first and move up in small steps until the size fits.
Key takeaways
- X: 512 MB for non-Premium; LinkedIn: 5 GB; Pinterest video ads: 2 GB (organic Pins state no video size), all from the platforms' own help pages.
- Size is bitrate times duration, so trimming seconds saves as much as lowering quality.
- With x264, CRF +6 roughly halves the bitrate and file size; 23 is the default and 17 to 28 is the sane range.
- Keep the dimensions when you can; reduce bitrate first, resolution last.
Published limits at a glance
From each platform's own help page, read on 2026-10-06. Limits can differ by account type, so check the composer when a file sits near the edge.
| Platform | File size | Length | Format notes |
|---|---|---|---|
| X (non-Premium) | 512 MB | Up to 140 seconds | Prompts you if the format is not supported |
| X (Premium) | Up to 16 GB | Shorter than 4 hours | 1080p; 720p for 2 to 4 hours |
| 5 GB | 15 minutes | MP4, MOV, AVI, WEBM, MKV, WMV and more; 256 × 144 to 4096 × 2304; 10 to 60 fps; 192 kbps to 30 Mbps | |
| Pinterest (organic Pins) | No video size stated | 4 seconds to 5 minutes | Web: MP4, M4V; Android and iOS: MP4, MOV, M4V; H.264 or H.265 |
| Pinterest (video ads) | 2 GB | 4 seconds to 15 minutes | MP4, MOV or M4V; H.264 or H.265 |
| YouTube | Not listed on this page | 15 minutes by default; longer once verified | MP4, AAC audio, H.264 recommended |
Find your case
| What you see | What it usually means | Do this |
|---|---|---|
| File is a few percent over the limit | Slightly too much bitrate | Raise CRF by 2 to 3 (step 2) |
| File is several times over the limit | Camera or screen-recording bitrate, or a long clip | Trim and re-encode (steps 1 and 2) |
| Size is fine but upload still fails | Length or format, not size | Check the limits table above |
| Compressed file looks worse than expected | CRF too high or preset too fast | Use a slower preset (step 3) |
Fix it step by step
Trim what you do not need
Size grows with duration. Cut dead air at the start and end before touching quality.
Re-encode with a higher CRF
ffmpeg -i in.mov -c:v libx264 -crf 26 -preset slow -c:a aac -b:a 128k out.mp4. The FFmpeg wiki says the CRF scale is exponential: +6 roughly halves the file size and -6 roughly doubles it.Use a slower preset
A slower x264 preset gives better quality for the same file size. Use the slowest preset you have the patience for.
Lower resolution last
Dropping 4K to 1080p cuts the pixels by 75% and the size with it, but only do it when the platform will show it at 1080p anyway.
Check the result against the limit
Look at the file size in your file manager, then run the check tool for your platform before uploading.
How CRF changes the size
Using the FFmpeg wiki's rule of thumb that +6 CRF roughly halves the bitrate, a 400 MB file at CRF 20 would land near these sizes (estimate, not a guarantee, because content changes the result).
| CRF | Relative size | Example from a 400 MB file at CRF 20 |
|---|---|---|
| 20 | 1x | 400 MB |
| 26 | about 0.5x | about 200 MB |
| 32 | about 0.25x | about 100 MB |
Past CRF 28 the picture usually looks clearly worse, so trim or lower the resolution before going further.
Check your file
Extension and MIME type are labels, not proof of the container. Dimensions and duration come from this browser's media reader. This does not detect codecs, bitrate, corruption or platform upload compatibility. Files and measurements are not sent anywhere.
Frequently asked questions
What is the maximum video size on X?
X Help says non-Premium accounts can upload videos up to 140 seconds long with a maximum file size of 512 MB. Premium subscribers can upload videos shorter than 4 hours with a maximum size of 16 GB.
How big can a Pinterest video be?
Pinterest's organic Pin spec states no video file size; its video ad spec lists up to 2 GB. For Pins, keep the file as small as quality allows and within 4 seconds to 5 minutes.
How big can a LinkedIn video be?
LinkedIn Help lists a maximum file size of 5 GB and a maximum duration of 15 minutes.
What CRF should I use to make a file smaller?
Start at the default 23, then raise it in steps of 2 or 3. +6 roughly halves the file; 28 is the upper end of the range the FFmpeg wiki calls subjectively sane.
Can I shrink a video without changing its dimensions?
Yes. Keep the same width and height and raise CRF or lower the bitrate; dimensions only change if you add a scale filter.
Sources
- X Help: Posting videos on X (official, checked 2026-10-06)
- Pinterest Help: Review Pin specs (organic Video Pin file types, length, aspect ratio, safe zones) (official, checked 2026-10-06)
- Pinterest Business Help: Ad specs (video ads: file types, size, length) (official, checked 2026-10-06)
- LinkedIn Help: Video sharing troubleshooting (formats and limits) (official, checked 2026-10-06)
- FFmpeg Wiki: Encode/H.264 (CRF, presets) (official, checked 2026-10-06)
Reviewed 2026-10-06. Steps not attributed to a source are general video practice or computed above.