Trying to upload a video from Google Drive and post it as a Reel via Facebook Graph API (resumable upload in n8n). I can’t get file_size in bytes to match — either I get Partial request (did not match length of file) or a straight‑up error.
If I hard‑code the “correct” size from an online MB→bytes converter, I get the partial error. Any other number gives an immediate error. Google Drive file_url also fails (403 robots.txt).
Looking for a way to get the exact byte size of the downloaded file in n8n and send it correctly in both start & transfer phases. Anyone done this before?
Method 2: I have success uploading the google drive video through the facebook graph api’s “Video Upload” option, and it succeeded, but when I try to post it as a reel (refer to last step of facebook API documentation), it says “video failed to upload”… what the hell is going on.
I’ve attached the errors, facebook api docs and json of my n8n workflowFacebook api
