Google FontTools - Convert fonts to different formats (TTF, WOFF, WOFF2)

Google FontTools - Convert fonts to different formats (TTF, WOFF, WOFF2)

I wanted a way to convert fonts to different formats without having to rely on online tools - it shouldn't be really hard - I guessed. And luckily, it isn't. :)

Install FontTools

Google has released an opensource font conversion program which we'll use. We'll need python, pip and some libraries - so, let's get them first.

Install python (v3)

Download and install python3:

Verify installation:

$ python3 --version
Python 3.8.5      # <-- expected output

Install pip (v3)

  • Linux and Mac: $ python3 -m pip --version
  • Windows: C:\> py -m pip --version


Verify installation:

$ pip --version
pip 20.0.2 from /usr/lib/python3/dist-packages/pip (python 3.8) # <-- output

Install FontTools and brotli


$ pip install fonttools
Collecting fonttools
  Downloading fonttools-4.21.1-py3-none-any.whl (849 kB)
     |████████████████████████████████| 849 kB 
Installing collected packages: fonttools
Successfully installed fonttools-4.21.1


$ pip install brotli
Collecting brotli
  Downloading Brotli-1.0.9-cp38-cp38-manylinux1_x86_64.whl (357 kB)
     |████████████████████████████████| 357 kB 
Installing collected packages: brotli
Successfully installed brotli-1.0.9

Download NotoSans

We test with NotoSans, a pretty heavy font, which makes the compressed sizes easy to compare.

Download the font from here: and decompress the contents.

We use the python3 REPL to try this out:

$ cd /path/NotoSans
$ python3
Python 3.8.5 (default, Jan 27 2021, 15:41:15)
[GCC 9.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from fontTools.ttLib import TTFont
>>> f = TTFont('NotoSans-Regular.ttf')
>>> f.flavor='woff2'
>>> f.flavor='woff'
>>> exit()

Verify converted files:

ls -alh
  rwxr-xr-x    2   manoj   manoj      4 KiB   Sat Mar 13 13:35:12 2021    ./
  rwxr-xr-x   16   manoj   manoj      4 KiB   Sat Mar 13 14:17:12 2021    ../
  rw-r--r--    1   manoj   manoj    444 KiB   Wed Sep 20 17:20:30 2017    NotoSans-Regular.ttf
  rw-r--r--    1   manoj   manoj    233 KiB   Sat Mar 13 13:35:13 2021    NotoSans-Regular.woff
  rw-r--r--    1   manoj   manoj    163 KiB   Sat Mar 13 13:34:54 2021    NotoSans-Regular.woff2

As you see, woff2 provides the best compression for usage on the web, as long as you don't have to support IE. Check browser support here: