Telegram error 400: Bad Request: PHOTO_INVALID_DIMENSIONS

sendPhoto (or a photo inside sendMediaGroup / InputMediaPhoto) was given an image whose dimensions Telegram will not accept as a photo. The Bot API documents two constraints: the photo's width and height must not exceed 10000 in total, and the width-to-height ratio must be at most 20. Very tall screenshots, long receipts, panoramas and banner strips break the ratio rule; huge scans break the sum rule.

The error is a raw server identifier, so there is no further detail. The file itself is fine as bytes; it is the image geometry that fails. Telegram's photo pipeline re-encodes and thumbnails images, and these limits protect that pipeline.

Sending the very same file with sendDocument works, because documents are not re-encoded and have no dimension rules.

{"ok":false,"error_code":400,"description":"Bad Request: PHOTO_INVALID_DIMENSIONS"}

Route all outbound images through a check that decides photo vs document based on the documented geometry rules. Prefer document for user-uploaded content of unknown shape, and photo only for thumbnails and images you control. When you relay images between users, keep the original file_id and resend it with the same media type Telegram assigned, which sidesteps re-validation entirely.

Byte-size ceilings are enforced separately and produce file is too big; an image can pass one check and fail the other. Both sets of numbers, with the documented source lines, are under file and media limits. Libraries raise their generic 400 class here, so match the uppercase identifier in the description.