Why your video won't upload (and how to fix it)

Upload boxes do not explain themselves. The message is written for whoever supports the platform, not for the person holding the file, but the wording still narrows the cause. Three messages show up again and again.

Unsupported file format, or a complaint about the file type: the platform read the file and did not recognize what is inside. The extension is not the issue. A .mov holding HEVC video and AC-3 audio is still a .mov, and that combination of codecs is what the uploader refuses.

Processing failed, try again: the upload arrived and the platform could not process it. Variable frame rate, an unusual codec, and a container it treats as damaged all surface here.

The file is too large, or the video is too long: the error usually names the cap. Those caps are published, and the table further down lists the main ones for YouTube, Instagram, and TikTok.

1. The codec inside the container. The container is the file wrapper (.mp4, .mov, .mkv); the codec is how the video and audio inside it are compressed. Phones and some exports write HEVC video with AC-3 or PCM audio, and platforms that ask for H.264 with AAC refuse them even though the extension looks fine. The Video Compatibility Checker reads the actual codecs from the file and compares them against each platform, so you do not have to guess.

2. A variable frame rate. Screen recordings and many phone clips change frame rate while they record. Players cope; upload pipelines that re-encode do not always, and the result shows up as audio drift, stutter, or a processing failure. Every platform in our specs database warns about variable frame rate. The Video Converter re-encodes to a constant frame rate.

3. A size or duration cap. Instagram treats 90 seconds as the comfortable reel length, TikTok lists 10 minutes as its typical upload cap, and Discord caps free uploads at 20 MB (raised from 10 MB in August 2026). When a file is under the duration cap but over a size budget, the Video Compressor re-encodes toward a target and shows the estimate before the job runs.

4. A damaged or unusual container. AVI, FLV, and MPEG transport streams play fine in desktop tools and bounce from most upload boxes. YouTube takes MKV; Instagram and TikTok do not. An export interrupted halfway can leave a container that platforms read as damaged. The Video Metadata Checker shows what the file actually is before you spend time converting it.

1. Diagnose the file. The Video Compatibility Checker reads codecs, resolution, frame rate, and bitrate in your browser, compares them against each platform, and names what fails. It takes seconds and uploads nothing.

2. Read the exact rules. Each platform page lists what it accepts, when it was last reviewed, and where the rules come from. Start with the YouTube upload specifications, then check the Instagram video specifications and TikTok video specifications for theirs.

3. Fix a codec or container mismatch by converting. The Video Converter re-encodes to H.264 and AAC in MP4, the combination every platform in the table accepts, and it passes the streams through untouched when they already fit.

4. Fix a size problem by compressing. The Video Compressor takes the cap the uploader named as a target size, shows its estimate, and re-encodes to land near it.

5. Clean the file before it goes public. Videos carry GPS coordinates, capture dates, and device details. The Video Metadata Remover strips them with a lossless remux, so the picture and sound are untouched.

The table is read from the same specs database the checker uses. Each column shows when that platform's requirements were last reviewed. Where a cell says Not specified, the tracked spec does not name a value for that field; the full warning list, including HDR and variable frame rate notes, lives on the platform's spec page.

Treat the caps as ceilings, not targets. Uploads below them can still fail for reasons the platform does not publish, which is one more reason to read the official sources linked from each spec page when a rejection makes no sense. The video codec cells carry the platform messages because that is the gray area: a codec can be accepted and still be the slower or riskier choice.

A file that passes the checker can still be refused. Platforms reject files for reasons outside their published specs and change those specs without notice, so a pass removes the usual causes rather than promising acceptance.

If everything checks out, retry once, then try a different browser and a wired connection before blaming the file. When the file is at fault and nothing above fixed it, re-export or re-record it: a fresh encode repairs damage that no conversion setting can read around.

Planning the next export? The video file size guide explains what bitrate does to size. One limit of ours, stated plainly: the converter, compressor, and remover take files up to 500 MB in your browser and up to 1 GB on our private server. The uploaded original is deleted as soon as the job ends, and the processed result sits at most an hour after you download it, never longer than 24 hours. The checkers never upload anything.