Upload Error Troubleshooting

Fixing file upload problems.

EPUB Upload Errors

"File too large"

EPUB exceeds 100MB limit.

• Compress images within the EPUB
• Use TinyPNG before embedding images
• Remove embedded fonts if not essential
• Resize images to web-appropriate dimensions

"Invalid EPUB file"

File is corrupted or not proper EPUB format.

• Run EPUBCheck validator
• Ensure file has .epub extension
• Re-export from your EPUB creation tool
• Don't rename .zip to .epub (must be properly packaged)

"Upload failed" or timeout

Network issue or browser problem.

• Check your internet connection stability
• Try a different browser (Chrome, Firefox, Safari)
• Disable browser extensions temporarily
• Clear browser cache and cookies

Cover Image Upload Errors

"Image too large"

• Compress image using TinyPNG or similar
• Reduce quality slightly (90% usually sufficient)
• Convert PNG to JPG if appropriate

"Invalid image format"

• Convert to JPG or PNG
• GIF and BMP not supported

"Image dimensions too small"

• Resize to at least 1600x2400px
• Maintain 2:3 aspect ratio
• Don't upscale low-res images — create new high-res version

General Upload Tips

• Use stable internet connection (not mobile data)
• Don't close browser during upload
• Wait for progress bar to complete
• Keep original files as backup

Recommended Browsers

• Google Chrome (latest version)
• Mozilla Firefox (latest version)
• Safari (latest version)
• Microsoft Edge (Chromium-based)

If uploads continue to fail, contact support with error message screenshot, browser/OS information, and exact steps when error occurs.