How to run wget downloads in the background

Long-running downloads should not depend on an open terminal window or a live SSH session. Background mode lets wget detach after startup so large transfers can continue after the shell prompt returns.

GNU wget detaches with --background or -b immediately after startup. Current GNU documentation also notes that, if no log path is specified with -o or --output-file, the detached run writes its status to wget-log by default, so an explicit log file keeps progress and errors easy to find.

Detached transfers still need normal operational checks. A background job can still stop early because of a network failure or a full filesystem, so keep the payload in a dedicated directory, preserve the log, and confirm the finished file before another process uses it.

1. Create a dedicated working directory for the detached transfer and its log file.

   $ mkdir -p ~/downloads/wget-background

   Keeping the payload and log together makes review and cleanup easier if the transfer fails or needs to be retried later.

2. Change into that directory before starting the transfer.

   $ cd ~/downloads/wget-background

3. Start the download in background mode with an explicit destination file and log path.

   $ wget --background --output-file=wget-download.log --output-document=release-2026-04.tar.gz https://downloads.example.net/release-2026-04.tar.gz
   Continuing in background, pid 45698.

   If --output-file is omitted, background mode writes to wget-log in the current directory.

4. Check that the reported PID is still the detached wget process.

   $ ps -p 45698 -o pid=,command=
   45698 wget --background --output-file=wget-download.log --output-document=release-2026-04.tar.gz https://downloads.example.net/release-2026-04.tar.gz

   If ps returns no rows, the transfer has already finished or exited, so the saved log is the next place to check.

5. Read the saved log after the transfer finishes.

   $ cat wget-download.log
   --2026-04-22 07:07:26--  https://downloads.example.net/release-2026-04.tar.gz
   Connecting to downloads.example.net (downloads.example.net)|203.0.113.50|:443... connected.
   HTTP request sent, awaiting response... 200 OK
   Length: 8388608 (8.0M) [application/gzip]
   Saving to: 'release-2026-04.tar.gz'
   
   ##### snipped #####
   2026-04-22 07:07:53 (308 KB/s) - 'release-2026-04.tar.gz' saved [8388608/8388608]

   The final saved line confirms that the detached transfer reached the end of the file cleanly.

6. Confirm the finished file exists at the expected size.

   $ ls -lh release-2026-04.tar.gz
   -rw-r--r-- 1 user user 8.0M Apr 22 07:07 release-2026-04.tar.gz

   A complete saved line in the log plus a non-zero file at the expected path is the clean success state for a background download.