This plugin displays your text in a textarea so you can use spellcheck plugins like Grammarly.
What is Overleaf textarea?
Overleaf Textarea is a unique Firefox add-on that transforms Overleaf's complex editor into a simple textarea. This modification permits more intricate spell-checking tools, such as Grammarly, to operate effectively in the editor. The add-on streams your data into the textarea, filters out commands/keywords, and positions the plain text over the PDF preview. Any revisions made in the textarea, either manually or via spelling tools, are analyzed and incorporated back into the editor.
Spellcheck in Overleaf is very basic. It is nothing compared to dedicated tools such as Grammarly. I used to copy and paste into Docs back and forward until recently. I created this chrome extension that copies the content of the file visible and the editor; filters the commands/keywords and pastes the plain text in a textarea (Right area). This textarea is displayed over the pdf preview. Extensions such as Grammarly can't check complex editors such as Overleaf, but only work in textareas. Changes made to the textarea, either by extensions such as Grammarly or yourself, are evaluated and changes are merged back to the editor.
Overleaf textarea may not be safe to use and it requires some risky permissions. Exercise caution when installing this add-on. Review carefully before installing.
Overleaf textarea is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.