Compress

Compress (@CompressBot) is one of several bots in this category with a name that states its job directly rather than an extended bio. Without published details, the safest expectation is the category standard: send an image, receive a smaller file back.

Because there is no confirmed information about which formats it accepts or how aggressively it compresses, it is worth sending a test image first if file size or quality matters for your specific use case, rather than relying on it blind for something important.

With no visible monthly-user count, it functions best as one option among several in this list — a quick try, with a more specifically documented bot like ShrinkImage Bot as a fallback if the result isn't what you expected.