Upload Issues

Upload is slow

Upload speed depends on your internet connection, specifically your upload bandwidth (not download speed). Most home connections have much slower upload speeds than download speeds. A few things you can try:

• Use a wired connection instead of Wi-Fi if possible
• Close other applications that might be using bandwidth
• Avoid uploading during peak network usage times
• Check your upload speed at a speed test site to see what your connection supports

Upload is stuck or the percentage jumps around

ZappFiles uploads files in chunks. If your connection is unstable, the progress bar might seem to jump or stall. This does not necessarily mean the upload has failed. ZappFiles will automatically retry failed chunks (up to 3 attempts per chunk). Give it a moment to recover.

If the upload stays stuck for more than a few minutes, try refreshing the page and starting the upload again. Make sure your internet connection is stable before retrying.

Upload stuck near 100%

When the progress bar reaches the end, the upload card switches from "Uploading" to "Finalizing". Your bytes are all in, and ZappFiles is assembling the uploaded parts and saving the transfer. For large files this step can take a moment. Keep the browser tab open until you see the confirmation screen. If you close it during "Finalizing", the transfer is never created and the recipient gets nothing.

Connection lost during upload

ZappFiles detects when your connection drops and automatically pauses the upload. When your connection comes back, the upload resumes from where it left off. You do not need to start over from scratch. Keep the browser tab open and it will pick back up automatically.

When a file cannot be read from your device

This means the browser lost access to the file itself, not the connection. Tapping resume will not fix it, because the upload has nothing left to read.

On a computer, the usual causes are a file that is still downloading from a cloud folder like Dropbox or Google Drive, and a file that was edited or moved after you selected it. Wait for the sync to finish and tap resume, or remove the file and add it again.

On a phone, it usually means you switched to another app while the upload was running, or the file came from your photo library rather than your device storage. Remove the file and add it again, stay on the ZappFiles tab while it uploads, and use WiFi for large files if you can.

File size limit reached

If your total file size exceeds your plan's limit, you will see a warning before you can start the upload. You can remove some files to bring the total under the limit, or upgrade your plan for a higher limit (up to 250 GB on Max).

Browser issues

ZappFiles works best on up-to-date versions of Chrome, Firefox, Edge, and Safari. If you are having persistent issues, try updating your browser or switching to a different one. Make sure you do not have any browser extensions that might block file uploads or network requests.

Still having problems?

If none of the above helps, reach out to us at info@zappfiles.com with details about what you are seeing and we will help you out.