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 in 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 cant 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.
You can Follow the below Step By Step procedure to install the Overleaf textarea Chrome Extension to your Chrome Web browser.
It is the Overleaf textarea Chrome extension download link you can download and install Chrome Browser.
Convert PDFs to LaTeX, DOCX, Markdown, and more
Writefull is automated proofreading for academic writing. This version of Writefull provides support for Overleaf.
This extension gets your bibtex citation through your text selection within one-click.
Lookup scholarly articles as you browse the web.
This extension provides a BibTeX reference for the active URL
Easy access on ArXiv! Rename the title to the paper's title. Add a button to navigate easily. Download PDF with meaningful filename.
An extension to show code implementations from Papers with Code directly in Google Scholar.
Open/edit latex files online using www.overleaf.com without the need of any software to be installed on your computer