I keep getting 400 checksum_mismatch. What's wrong?

The API refuses a chunk with 400 checksum_mismatch when its bytes don't match the X-Content-SHA256 you sent.

Usual causes#

• Hashing the whole file instead of the chunk.
• Sending the hash in base64 instead of hex.
• Reading the wrong byte range for the chunk.
• Something in between changing the bytes (rare; resending fixes it).

Hash exactly the bytes you send, as lowercase hex, and resend.

Learn more#

• Errors
• Limits