I assume they used the "prepare.sh" script for that 50M file: https://github.com/madmurphy/libconfini/tree/master/dev/tests/performance https://github.com/madmu

I assume they used the "prepare.sh" script for that 50M file: https://github.com/madmurphy/libconfini/tree/master/dev/tests/performance https://github.com/madmurphy/libconfini/tree/master/dev/test... (you need to clone the repo to run it, because it depends on some other files in there). The file it generates is not valid TOML though; even if you fix the obvious syntax issues you run in to issues like: % tomlv ./big_file.ini Error in './big_file.ini': toml: line 35: Key 'section' has already been defined. Perhaps tomlc99 doesn't check for this; I didn't try it. Maybe I should add something to toml-test for this; while I agree that 50M files are somewhat rare[1] and that performance isn't a huge consideration, it's not entirely unimportant either, and this can give people a bit of a "is the performance of my parser horribly atrocious or roughly fine?" kind of baseline. [1]: One use-case I have is that I use TOML for translation files (like gettext .po, except in, well, TOML) and in a large application with a whole bunch of translations I can see that adding up to 50M.