An upload that fails partway through — or won't start at all — is one of the most frustrating things about sending a large file. Before you try uploading the same file for the fifth time, here's what's actually likely to be going wrong, and how to fix each one.
1. The file is bigger than your plan allows
This is the most common cause, and the easiest to check. Every plan has a per-file size limit: 4 GB free, 60 GB on Basic, and 500 GB on Pro. If your file is over your plan's limit, the upload will be rejected with a message telling you so — check the file's actual size against your plan's limit before assuming something else is wrong.
2. Your connection dropped mid-upload
A large upload is a single, continuous connection from your browser to the server for as long as it takes to finish. If your Wi-Fi drops, you switch networks, your laptop goes to sleep, or you close the browser tab partway through, the upload stops and currently has to start over from the beginning — there's no resume yet for an interrupted upload. For anything large, the fix is simple: stay on a stable connection, keep the tab open, and keep your device awake until it finishes.
3. You're on mobile data instead of Wi-Fi
Mobile connections are usually slower and less stable than Wi-Fi, which matters more the larger the file is. A multi-gigabyte upload over mobile data takes longer and is more likely to get interrupted by a signal drop. Switch to Wi-Fi for anything beyond a quick, small file.
4. You've hit a daily or monthly upload limit
Guest and free-account uploads are capped at a certain number of uploads per day. If you're testing repeatedly or sending several files in a short window, you may be hitting that cap rather than a file-specific problem. Paid plans have much higher daily and monthly limits.
5. You're sending more files than your plan allows at once
Free accounts can upload up to 7 files in a single batch, Basic up to 25, and Pro has no per-upload file-count limit. If you're dropping in a large batch of individual files and it's failing, try trimming the batch down or uploading it as a single zipped folder instead.
6. A browser extension or network restriction is interfering
Ad blockers, aggressive privacy extensions, or a restrictive office/school network firewall can occasionally block upload requests. If nothing else here explains the failure, try the upload in a private/incognito window with extensions disabled, or on a different network, to rule this out.
How to give a large upload the best chance of succeeding
- Check the file size first against your plan's limit before uploading.
- Use a stable Wi-Fi connection, not mobile data, for anything large.
- Keep the tab open and your device awake for the full duration of the upload.
- Upload one large batch at a time rather than running multiple big uploads simultaneously.
- For very large files, expect it to take time. A multi-gigabyte upload can reasonably take minutes to hours depending on your connection speed — that's normal, not a sign it's broken.
The bottom line
Most upload failures come down to one of a few things: a file over your plan's limit, an interrupted connection, or a daily cap. Check those first before assuming something's broken. Try your upload again on a stable connection, and if it still won't go through, our support team can help track down what's happening.
