Microsoft Editor is a grammar and spelling checker that analyzes your writing and suggests corrections and improvements. Use it wherever you enter text, from Word to social media posts.
Microsoft Word for Windows PCs and Apple Macs has had spelling and grammar checking for decades, but these days we spend a lot of our time writing online, not just on the computer. Microsoft Editor is a web-based grammar and spelling checker that works everywhere you type online.
Word is now available as a web app and you can create business and personal documents in the browser. This is where Microsoft Editor works best and has the most features. It is best with an Office 365 subscription, but there is a free Word web app and free version of Editor. You do get slightly fewer features with them both, but they are still very useful.
Micrsoft Editor browser extension
Grammarly has been available as a web browser extension for years and it is great for checking your typing online, such as in social media posts, emails, web forms and other places. Now it has a competitor and Microsoft Editor performs similar tasks, checking your spelling and grammar everywhere you type online.
Microsoft Editor is an alternative to Grammarly and it has similar features and functions. Get Microsoft Editor for Chrome from the Chrome Web Store or get Microsoft Editor for Edge – last time I looked there were 1m+ users and it has a great rating. It works on Windows PC and Apple Mac, probably Linux too.

An icon is added to the browser toolbar and clicking it enables you to turn the spelling and grammar checkers on or off. Those are free. There is an extra feature only for Office 365 subscribers called Refinements and it enables checking for more subtle problems, like over used cliches and the wrong writing style, such as casual when it should be formal.
Wherever you type text on the web, like social media posts, forms, comments and more, your typing is automatically checked and errors are highlighted. Posting in a forum? Get your spelling and grammar automatically checked.

Here is a Facebook post with a typing slip, it works fine with social media.

Click the icon in the browser toolbar and then click the gear icon to open the plugin preferences. There are four options for spelling, like ignoring uppercase words, URLs and words with numbers. There are 18 options for grammar checking, like adjective used instead of adverb, verb use, spaces, punctuation, missing commas and more.
There is not much to choose between free Microsoft Editor and free Grammarly browser extensions. Both do a great job, but I think Grammarly is a slightly better browser extension. It shows helpful icons and popup boxes and catches more errors. MS Editor is visually a bit dull in comparison.
Microsoft Editor for Word web app
Word web app is a browser-based version of Microsoft Word that can be used at the onedrive.com website or office.com either for free or with an Office 365 subscription. This is where Microsoft Editor shines its brightest. The browser extension is not needed for it to work.
Create a new document in the Word web app at onedrive.com or office.com and enter some text. The more the better and it will not work unless there is sufficient text. Better still, load a document you have already written.

Click the Editor button at the right side of the Home toolbar and a whole panel opens that is dedicated to an analysis of your writing and there are a lot of suggestions for improvements.
Check for plagiarism in Word
Below the Editor Score is a plagiarism checker. This is useful when checking documents written by other people and making sure they are unique. It is also useful for your own articles, for example, if you use phrases or sentences copied from elsewhere, or even if you use a well-known phrase and cannot remember the original author.

Click Check for similarity to online sources and you not only see if the article is original, you can also step through any parts that exist elsewhere on the web. They are highlighted and there is even an option to automatically enter a citation and get more places where it is used on the web, which is useful. That will save you having to use other online plagiarism detectors or forgetting your citations.
Refine Word documents
In the Corrections section of the Editor sidebar are spelling and grammar checkers and these work for free. These show the number of errors and clicking them enables you to step through each of the errors and either correct them yourself or accept the suggested fixes. This is standard and you can spot errors and correct them as you type or go through the document afterwards making corrections.
The Refinements section is only for premium users, which are Office 365 subscribers. However, you may be offered a month’s free trial of the premium features. I was.

It has some interesting features and it looks at things like clarity, conciseness, formality, inclusiveness, perspectives and more. A number next to each one shows how many errors there are.
These are only suggestions, but it is useful to step through them and see what is suggested. Take a look at this Perspectives suggestion for example.

It has detected a large monetary amount, $26.2 billion and suggested saying $26.2 billion (about $81 per person in the US). I’m not sure its use is right here, but it is a very surprising and clever suggestion and it shows that there is a bit of intelligence behind the Microsoft Editor. This goes beyond grammar checking and is almost like having an AI suggesting and writing things. It makes me wonder what else it might suggest.
Predictions, stats and more
There is an option to enable predictive text. It basically guesses what word you will type next and suggests it. It appears as light gray text and you can press Tab to enter the word or just carry on typing over the top of it. It is not needed for short words, but it is very useful for long words if you are a slow typist. You just hit tab if you see the word you want suggested.

A Document Stats panel shows word, character and paragraph counts, reading and speaking times, and the readability score. If you see it is hard to read, you could try to edit the document and make it easier. It highlights uncommon words, which is not necessarily a problem, but is something you can check.
Summing up Microsoft Editor
The Chrome and Edge browser extension is good, but if you already have Grammarly, it is not worth switching to Microsoft Editor. If you don’t have a spelling and grammar checker, it is worth considering. Browsers already do some basic checking, but this goes further.
Microsoft Editor in the Microsoft Word web app is excellent if you are an Office 365 subscriber and have access to all the features. It points out many errors and it comes up with some interesting and useful suggestions for improving the text. Not all the features are available for free users of the Word web app, but there are enough to make it useful.