Instagram and TikTok re-compress every upload. If your file is too big or in an odd format, they compress it harder – and it looks worse. Preparing the video yourself gives a sharper result and a faster upload.

Best settings

Resolution: 1080 × 1920 (vertical, 9:16).
Frame rate: 30 fps (60 fps only if the original is 60).
Format: MP4 (H.264).
Size: keep it reasonable – a 30–60 second clip of 20–60 MB uploads quickly and keeps detail.

Compress it with Video Compressor & Resizer

Open the app and select your video.
Choose 1080p as the resolution, or set a target size in MB.
Keep the format as MP4 and compress.
Upload the new file to Reels or TikTok.

4K video? Uploading 4K does not make Reels sharper – they are shown at 1080p. Compress to 1080p first to save time and data.