Spot the difference on the web

Davide Alberani 1ddfb76c85 improve SMTP SSL support 2 years ago
conf 2a88d5ab7a fixes #16: support SMTP authentication 2 years ago
dist 678a8bccc5 update loadash 3 years ago
docs 4261623d1a add documentation 6 years ago
ssl d249420df3 ssl directory 6 years ago
storage 85cbdc00ad commit to git repository 6 years ago
.gitignore 85cbdc00ad commit to git repository 6 years ago
Dockerfile cadc6ec2d8 Docker file 6 years ago
LICENSE.txt 3e5be6d58c skeleton of scheduler 6 years ago f3e0d9e095 fix #18: update Axios library 3 years ago 1ddfb76c85 improve SMTP SSL support 2 years ago 2678000d68 update file permission 6 years ago


Spot the difference on the web.

Tired of clicking F5 waiting for a change on a web page? Define a list of pages to watch, and receive an email when something has changed.

Install, run, develop and debug


Just run:


Old-fashioned installation

To install it:

sudo python3
# if you want to install these modules for an unprivileged user, add --user and remove "sudo";
# if you want to upgrade the versions already present in the system, also add --upgrade
sudo pip3 install lxml
sudo pip3 install pytz
sudo pip3 install apscheduler
sudo pip3 install requests
sudo pip3 install sqlalchemy
sudo pip3 install tornado
git clone
cd diffido
./ --debug

Now you can point your browser to http://localhost:3210/

You can also run the server in https, putting in the ssl directory two files named diffido_key.pem and diffido_cert.pem


You can edit the conf/diffido.conf file (Python syntax) to change the global settings; you almost surely have to configure the SMTP settings, at least.

Each schedule has its own web page GUI; the settings should be pretty self-explanatory, except:

  • XPath selector: define which portion of a web page to consider
  • minimum change: float between 0.0 and 1.0, which represent the minimum amount of the page (in percentage of number of lines) that has to be changed to send a notification; if left empty, any change will be notified
  • crontab: a complete crontab definition, to specify the period of the check


See the docs/ file for more information about how to contribute.

Technological stack

License and copyright

Copyright 2018-2021 Davide Alberani

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.