Heroku procfile "No such process type web defined in Procfile" error

Processes to be run on Heroku are defined in a simple text file called: Procfile

The Profile contains a line that defines how each of the processes in your application will run. This will be language specific and examples can be seen on the Heroku Devcenter Procfile article

Please note that the Procfile must be spelt exactly, with the first letter capitalized an all others lower case. There is no file extension for the Procfile. This Procfile should be placed in the root of your project and committed to your local git repository before doing a git push heroku master.

Should you mis-type the filename after it has been added to git, you can rename it using git with the command

git mv ProcFile Procfile

The renamed file will be staged so you can commit the changed file with the command

git commit -m "corrected name of Procfile"

I found the solution myself, from here: https://stackoverflow.com/a/7641259/556006

I had the same problem and I just now I found what was wrong. I first accidently called the file ProcFile instead of Procfile. Simply renaming that file did not get picked up by git. I had to do a git rm ProcFile -f first and then add a new (correctly named) Procfile. After that, it got pushed correctly by git and got picked up correctly by Heroku.

I just had this issue myself, but in my case, I was missing a space between web: and the starting command in the Procfile.

For example, I had it wrong this way:

web:gunicorn run:app

Fixed it by adding a space after the colon:

web: gunicorn run:app