Cat command

Download content of a file-like object identified by B2 URI directly to stdout.

If the tqdm library is installed, progress bar is displayed on stderr. Without it, simple text progress is printed. Use --noProgress to disable progress reporting (marginally improves performance in some cases).

To access SSE-C encrypted files, please set --sourceServerSideEncryption=SSE-C. The default algorithm is set to AES256 which can by changed with --sourceServerSideEncryptionAlgorithm parameter. Using SSE-C requires providing B2_SOURCE_SSE_C_KEY_B64 environment variable, containing the base64 encoded encryption key.

Use –write-buffer-size to set the size (in bytes) of the buffer used to write files.

Use –skip-hash-verification to disable hash check on downloaded files.

Requires capability:

  • readFiles

b2 cat [-h] [--noProgress] [--sourceServerSideEncryption {SSE-C}]
       [--sourceServerSideEncryptionAlgorithm {AES256}]
       [--write-buffer-size BYTES] [--skip-hash-verification]

Positional Arguments


B2 URI pointing to a file, e.g. b2://yourBucket/file.txt or b2id://fileId

Named Arguments


progress will not be reported

Default: False


Possible choices: SSE-C


Possible choices: AES256

Default: “AES256”


Default: False