Progress meter

curl has a built-in progress meter. When curl is invoked to transfer data (either uploading or downloading) it can show that meter in the terminal screen to show how the transfer is progressing, namely the current transfer speed, how long it has been going on and how long it thinks it might be left until completion.

The progress meter is inhibited if curl deems that there is output going to the terminal, as the progress meter would interfere with that output and just mess up what gets displayed. A user can also forcibly switch off the progress meter with the -s / --silent option, which tells curl to hush.

If you invoke curl and do not get the progress meter, make sure your output is directed somewhere other than the terminal.

curl also features an alternative and simpler progress meter that you enable with -# / --progress-bar. As the long name implies, it instead shows the transfer as a progress bar.

At times when curl is asked to transfer data, it cannot figure out the total size of the requested operation and that then subsequently makes the progress meter contain fewer details and it cannot, for example, make forecasts for transfer times, etc.

Units

The progress meter displays bytes and bytes per second.

It also uses suffixes for larger amounts of bytes, using the 1024 base system so 1024 is one kilobyte (1K), 2048 is 2K, etc. curl supports these:

The times are displayed using H:MM:SS for hours, minutes and seconds.

Progress meter legend

This is the progress meter shown for each single transfer when doing them in a serial manner. When parallel transfers are enabled, curl instead uses the format described below.

The progress meter exists to show a user that something actually is happening. The different fields in the output have the following meaning:

% Total  % Received % Xferd Average Speed          Time             Curr.
                            Dload  Upload Total    Current  Left    Speed
0  151M  0 38608    0     0  9406      0  4:41:43  0:00:04  4:41:39  9287

From left to right:

Parallel progress meter

When --parallel is used, curl can do many transfers simultaneously and then the above mentioned progress meter does not really work as it then needs to tell the user the status about a large number of transfers in a single status line.

When curl does parallel transfers, it might only have size information about a subset of the data until late in the process, which makes it often show a few blank fields. For example it cannot tell a total expected transfer time until it knows the expected content size of all involved transfers.

DL% UL%  Dled  Uled  Xfers  Live Total     Current  Left    Speed
88  --  2682K     0    57    70  --:--:--  0:00:07 --:--:-- 1190k

From left to right: