I have a custom operating system with the name KompassOS (www.kompassos.nl) and sometimes we need to upload big ISO files to cloudflare. But if the files all the files bigger than 300MB you have to upload with the S3 API.

So Need to upload large files (>300MB) to Cloudflare R2? Here’s how to do it with a single rclone command without creating config files.

Prerequisites

  1. Create an R2 bucket in your Cloudflare dashboard
  2. Generate API credentials in Cloudflare R2 → Manage R2 API Tokens
  3. Install rclone

The Command

rclone copy ./your-file.iso ':s3,provider=Cloudflare,access_key_id=YOUR_ACCESS_KEY,secret_access_key=YOUR_SECRET_KEY,endpoint=YOUR_ACCOUNT_ID.r2.cloudflarestorage.com,no_check_bucket=true,force_path_style=true:your-bucket/'

Key Parameters

  • provider=Cloudflare - Tells rclone to use R2-specific settings
  • no_check_bucket=true - Prevents bucket creation attempts (avoids 403 errors)
  • force_path_style=true - Ensures compatibility with R2’s API
  • Replace YOUR_ACCOUNT_ID with your Cloudflare account ID
  • Replace YOUR_ACCESS_KEY and YOUR_SECRET_KEY with your R2 credentials
  • Replace your-bucket with your bucket name

Why This Works

Regular file uploads in web interfaces are limited to 300MB. This method uses rclone’s multipart upload capability, allowing files of any size to be uploaded directly to R2 storage.

Perfect for ISOs, backups, and other large files!

Happy uploading :)