I don't know why it takes so long for this case.

Papaparse can parse a 50MB file in about 1 second in my machine. It’s great.

However, I’m not sure what is special about this csv file but it’s just 400KB but takes 60 seconds to parse, and the whole browser was stalled meanwhile.

I’ve tried to tweak some settings and looks like the problem will only occur if:

• We don’t enable Stream option
• We enable the Skip Empty Lines option

Changing any of those will make it work normally again. I’m just wondering why those options affect the performance so significantly.

https://www.papaparse.com/demo

evil_csv_file.csv

[pokoli]

@bezrodnov I will be happy to merge a PR that fixes that. As already commented I think Array.filter is the way to go if that does not break anything. Otherwise we can consider any other solution.

[bezrodnov]

BTW we are using papaparser in our project and we’ve faced exactly the same issue on production recently. And I can confirm that the code gets stuck in this “for-with-array-splice” loop - in our case the number of elements in the array was slowly decreasing from 1+ million to ~200 records (which took more than 10 minutes). And I guess MS Excel could cause the file to look that weird.