The extension is not that bad, but it keeps telling me that there are mistakes but they aren't mistakes and it wants to separate the words from each other and mess up the whole thing or even replace my mistake words with worse words but the extension is not bad, so it deserves a solid 4-star.

Bevor1

Très bon correcteur mais il n'identifie pas automatiquement la langue de l'utilisateur ce qui est très énervent car je doit changer a chaque fois langue de correction qu'il ne mémorise pas.

If you aren't ready to pay for Grammarly, this is your grammar checker of choice. Free versions of these two services are more or less similar, and both are good

However, the premium version of Grammarly is just better. Outrageously expensive and English-only -- yes. But in terms of convenience, accuracy, and usefulness, LanguageTool is not on the same level (yet?), unfortunately

(I use LanguageTool, by the way)

Ce module a tendance à vous imposer des virgules qui n'ont rien d'indispensable.

Das Language Tool funktioniert recht zuverlässig in Hinblick auf die Orthografie, die Grammatik-Hilfe ergibt bisweilen recht abenteuerliche Vorschläge. Ich rate all jenen Mitbürgern dringend zur Installation, die bar jeglicher Bildung aggressiven Unfug, Beleidigungen und extremistische Hetze in die sozialen Netzwerke posaunen.

Early days for me but it seems to do a reasonable job.