Spell Check and Grammar for Obsidian on Mac

Obsidian on Mac has a built-in spellcheck setting but no grammar checking at all, and Grammarly does not run inside it. You have three realistic options: switch on Obsidian's own spellcheck, install the free Harper plugin for inline grammar checking, or use Charm. One thing to say up front, because it matters: Obsidian is an Electron app, so Charm does not correct your typing live in it. In Obsidian, Charm uses Fix Selection instead. Type your note, select the text, press Option-Command-V, and Charm fixes spelling and grammar in one pass.

Why doesn't spell check work properly in Obsidian?

Obsidian is built on Electron, which wraps a web page in a desktop shell. Its editor draws its own text surface rather than using a standard macOS text field, so the system spelling and grammar layer that Mail and Notes rely on has no proper hook into it. Corrections that feel automatic elsewhere on your Mac simply do not fire here.

The most common complaint is oddly specific. Red squiggles appear under misspelled words, but right-clicking gives you no replacement suggestions, so you are told there is a mistake and left to fix it yourself. Obsidian users have logged this on the community forum as a macOS-specific spellcheck failure.

It is the same family of problem we cover in why autocorrect stops working in some Mac apps and in our look at whether Apple Intelligence works in Obsidian.

How do you turn on Obsidian's built-in spellcheck?

Open Obsidian, go to Settings, choose Editor, and switch on Spellcheck. Obsidian then checks your notes against the macOS system dictionary and underlines words it does not recognise. It is off for some users by default, so it is worth checking even if you assumed it was already running.

To stop it flagging names, jargon and project codewords, right-click an underlined word and choose to learn or add it. That entry goes into the macOS dictionary and follows you into other apps. Our guide on adding words to your Mac dictionary covers where those entries live and how to edit them later. Charm keeps its own personal dictionary too, so a word you teach it is respected on every correction path.

What this setting will never give you is grammar checking. Obsidian has no concept of a wrong tense, a missing word, or a subject that does not agree with its verb.

Why doesn't Grammarly work in Obsidian?

Grammarly does not appear in the Obsidian desktop app, and there is no official plugin. Grammarly's Mac integration attaches to text fields it can recognise, and Obsidian's editor is not one of them. So the floating Grammarly button that shows up in other apps never arrives, and nothing happens.

This is well documented by users rather than by Grammarly. There is a long-running forum thread on Grammarly not working with Obsidian, plus a standing community request for a Grammarly plugin that has been open for years.

The usual workaround is to copy a note into Grammarly's web editor, fix it there, and paste it back. That breaks your flow, mangles Markdown on the way through, and sends your private notes to a server. For journals, client work or unpublished drafts, that last point is often the dealbreaker. More on that tradeoff in what on-device AI privacy actually means.

What is Harper and should you use it?

Harper is a free, open-source grammar checker from Automattic, and it has an official Obsidian plugin. It runs entirely offline, it is fast, and it works inline inside the Obsidian editor, underlining grammar problems as you write. If you want something that behaves like Grammarly but stays on your machine, this is the closest thing available.

Installing it takes a minute. Open Settings, go to Community plugins, search for Harper, install and enable it. The official Harper documentation for Obsidian covers the settings, including which rules to switch off if it is being fussier than you want.

We will be plain about this: inside Obsidian specifically, Harper does something Charm does not. It corrects inline, in the editor, as part of the app. It costs nothing and the code is open. If Obsidian is where nearly all of your writing happens, install Harper and you are done. That is an honest recommendation, and we would rather give it than pretend otherwise.

How does Charm work in Obsidian?

Charm works in Obsidian through Fix Selection. Because Obsidian is an Electron app, Charm detects that automatically, switches out of live inline correction, and tells you it has done so. You then write your note as normal, select the paragraph or the whole document, and press Option-Command-V. Charm corrects spelling and grammar in that selection in a single pass.

In practice this suits note-taking well. Few people want a tool rewriting text mid-thought while they capture ideas, and a pass at the end of a note is a natural point to tidy up. The same shortcut works in browsers and every other Electron app.

Everything runs on-device. No account, no cloud, no connection needed, which means your vault stays yours. Charm fixes mechanics such as spelling, agreement, tense and punctuation, and it deliberately never rewords your sentences into something that sounds like a machine wrote it. It supports English, needs macOS 14 or later, and costs $9.99 once for up to three Macs with a 14-day money-back guarantee.

Which should you choose?

Choose Harper if Obsidian is basically your writing app. Choose Charm if Obsidian is one of several places you write and you would rather have one tool covering all of them. Running both is perfectly reasonable too: Harper inline in the vault, Charm everywhere else.

The wider point is where your writing actually happens. Notes start in Obsidian but end up in Mail, Pages, Scrivener, a browser form or a message. Charm covers that whole path for $9.99 paid once. There is no subscription, no renewal date and no monthly fee for a writing tool you use every day, and that single purchase covers every app on your Mac rather than one editor. It adds word prediction on top, running inline as you type in native apps even though Obsidian gets the selection-based treatment. Our guide to checking grammar in every Mac app goes app by app.

Frequently asked questions

Does Charm correct my typing live inside Obsidian?

No. Obsidian is an Electron app, so Charm switches automatically to Fix Selection. You type your note normally, select the text you want cleaned up, and press Option-Command-V. Charm corrects spelling and grammar in that selection in one pass. Live inline correction as you type is reserved for native Mac apps such as Mail, Notes, Pages and TextEdit.

Why does Obsidian show red squiggles but no suggestions on my Mac?

This is a reported macOS issue in Obsidian where the editor draws the misspelling underline but the right-click menu offers no replacement words. Obsidian users have logged it on the community forum. Restarting Obsidian sometimes helps, but the reliable fix is to use a checker that does not depend on that menu, such as the Harper plugin or Charm's Fix Selection shortcut.

Can I use Grammarly in Obsidian?

Not in the desktop app. Grammarly's Mac integration relies on hooks that Obsidian's editor does not expose, and there is no official Grammarly plugin. Obsidian users have been asking for one on the community forum for years without a result. Harper and Charm are the practical alternatives.

Is Harper or Charm the better choice for Obsidian?

If Obsidian is where nearly all of your writing happens, Harper is the better choice. It is free, open source, offline, and it works inline inside the editor because it is a purpose-built plugin. Charm is the better choice when Obsidian is only one of the places you write, because the same tool covers Mail, Notes, Pages, Scrivener and everywhere else on your Mac.

Do Obsidian, Harper and Charm send my notes to a server?

No. Obsidian's built-in spellcheck uses the local macOS dictionary. Harper runs entirely offline as a local rule and dictionary engine. Charm runs fully on-device with no account and no cloud connection. All three are safe for private journals, client notes and unpublished work.