"Free 30 Minutes Trial" is not native English. "Free 30 Minute Trial" would be better; but I think the sentence is a little confusing. I presume you mean you can convert 30 minutes of audio for free, not that the trial account is only valid for 30 minutes from creation. I would do "Clean 30 minutes of audio for free. No Credit Card needed." or similar. The sale page which says "Get 30 minutes credit to try the service out." is better, and "30 minutes" does sound correct on that page.

In your FAQ, you say: "Currently we remove lip smacks, saliva crackle, mouth clicks and harsh parts of breathing (not the whole breath). If you want to remove a particular mouth sound (ex. Chewing), write us in the chat as a feature request." I don't think most English speakers would understand what "harsh parts of breathing" are. Typically a parenthetical example in English would be written "(e.g. chewing)" not "(ex. Chewing")".

Your question "What filetype and sizes do you support?" doesn't answer what filetypes you support, and I suspect the singular "filetype" was a grammar error. You also write "We have an audio file size limit of 1.5G per file or in case you are uploading multi-track and a total file size of 2 GB. ". The part that says "or in case you are uploading multi-track and" doesn't make any sense in English. I think you mean "We support file sizes up to 1.5GB per file for single-track files, or 2GB if you are uploading a multi-track file as separate files." but I'm not sure.

In general I don't understand why each selling point has a separate FAQ page but the FAQs are often not related to the selling point. I don't think people think the "Mouth Sound Remover" page is the one that lists file size support, while the "Stutter Remover" page is the one that lists the maximum number of tracks per project.

Your integrations page lowercases "cleanvoice" whereas other pages write it as "Cleanvoice".

Under integrations, you have a section called "Markers Export". This should probably be "Export Markers" or "Marker Export".

Under "How to Export Edits", you probably don't want to capitalize "Results" or "Editor" unless these are supposed to be title cased, in which case you probably want to title case all of them.

Under your pricing FAQ you have "Does my credit expire at end of the month? Your credit will reset every billing month. Unused credit will be lost." This is needlessly confusing. You use the verbs "expire", "reset", and "be lost" to describe the same thing, and you don't actually answer the question. Also you don't want "at end of the month", you want "at month's end" or "at the end of the month". I would rewrite as "Does my credit expire at the end of each month? Yes. Credit resets every month and cannot be carried over to future months. Unused credit will be lost." This is a terrible business model, though, and so I suggest you not do this. Either sell as a subscription or sell as a credit model, not both, this is gross.

In general I think you want to pay someone who is a professional English copywriter to fix your website. Cheers.

Edit: I just noticed your changelog is powered by a service called Headway. I am not sure if you also made Headway, but Headway's website is also in need of English copyediting.