File Size and Format Limits
Upload limits per file type, per-platform requirements at publish time, and how to compress files that exceed limits.
File upload failures are almost always caused by one of three things: a format Flamel does not accept, a file that exceeds Flamel's upload limit, or a file that passes Flamel's limit but exceeds the destination platform's limit at publish time.
Flamel Upload Limits
- Images: JPG, PNG, WebP, GIF, or HEIC (HEIC is converted automatically). Keep images under 50 MB; very large images are rejected before processing.
- Videos: MP4 or MOV. Large videos are supported and optimized automatically; extremely large files may skip optimization, so compress before uploading when you can.
Platform Limits at Publish Time
Flamel warns you when a file exceeds a platform's limit before it attempts to publish. Images just need to clear Flamel's image limit above; the video limits are where platforms differ:
- Instagram feed: video up to 60 minutes.
- Instagram Reels: uploads up to about 15 minutes, but keep them under roughly 3 minutes for the best reach.
- Stories (Facebook or Instagram): up to 60 seconds per segment.
- Facebook: video up to 240 minutes, files up to 10 GB.
- LinkedIn: video up to about 10 minutes.
- TikTok: video up to 10 minutes. File size caps run roughly 72 MB on Android and 287 MB on iOS, with much larger files allowed via web upload.
- X (Twitter): video up to 2 minutes 20 seconds on a standard account; verified/Premium accounts can post longer.
Platforms Change These Often
These limits move as each platform updates its product. If a file is close to a limit, confirm the current number on the platform itself before relying on it.
Troubleshoot a Failed Upload
Match your symptom to the fix:
- Unsupported format error: convert the file to JPG, PNG, or MP4 using a desktop tool.
- File too large: compress or resize before uploading (see below).
- Progress bar stuck: refresh, then try a smaller batch of 5 to 10 files.
- Colors look wrong or distorted: save in a standard RGB color profile, not CMYK.
Compress Images
Most photo editors let you adjust JPG quality. Setting it to 80% typically reduces file size by 70%+ with no visible quality loss.
Free tools:
- ImageOptim (Mac desktop)
- Squoosh (web, squoosh.app)
- Sharp (command line)
Compress Video
Handbrake (free desktop) or FFmpeg (command line) can dramatically reduce video file size. H.264 encoding at an 8 Mbps target bitrate handles most social content while staying well under platform limits.
Recommended Dimensions
Use these sizes for the best results across platforms:
- Square image: 1080 x 1080
- Vertical video, Stories, Reels: 1080 x 1920 (9:16)
- Horizontal video: 1920 x 1080 (16:9)
- Link share image: 1200 x 630