Much like the unix tee utility, wtee duplicates standard input to standard output, while also making the piped data viewable on a web page. For example:

tail -f /var/log/debug | wtee | nl


The latest stable versions of wtee can be installed from pypi:

$ pip install wtee

The development version is available on github and can also be installed with the help of pip:

$ pip install git+git://github.com/gvalkov/wtee.git

A self-contained executable requiring only Python is also provided (built with pex):

wget https://github.com/gvalkov/wtee/releases/download/v1.0.1/wtee

Wtee works with Python 2.7 and newer. Using it with Python >= 3.3 is encouraged.


The wtee tool does two things:

  • Duplicates standard input to standard output.
  • Starts a local http server on which the piped data can be viewed.

Wtee’s server-side functionality is summarized in its help message:

Usage: wtee [-h] [-d] [-v] [--output-encoding enc] [--input-encoding enc]
          [-b addr:port] [-r path] [--no-wrap-lines]

A webview for piped data.

General options:
  -h, --help                show this help message and exit
  -d, --debug               show debug messages
  -v, --version             show program's version number and exit
  --output-encoding enc     encoding for output
  --input-encoding enc      encoding for input and output (default utf8)

Server options:
  -b, --bind addr:port      listen on the specified address and port
  -r, --relative-root path  web app root path

User-interface options:
  --no-wrap-lines           initial line-wrapping state (default: true)

Example command-line usage:
  tail -f /var/log/debug | wtee -b localhost:8080 | nl

Reverse proxy configuration


  1. Run wtee, binding it to localhost and specifiying a relative root of your liking. For example:
$ tail -f logfile | wtee -b localhost:8084 -r '/wtee/'
  1. Add the following location directives to nginx.conf:
location /wtee/ws {
    proxy_pass http://localhost:8084/wtee/ws;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";

location /wtee {
    proxy_pass http://localhost:8084;


Wtee’s favicon was created from this icon.


Wtee is released under the terms of the Revised BSD License.