Proofreader for Obsidian

AI-based proofreading and stylistic improvements for your writing. Changes are inserted as suggestions directly in the editor, similar to the suggested changes feature in word processing apps.

Table of contents

• Features
• Installation & setup
  • Plugin installation
  • Get an API key
• Usage
• Visual appearance of the changes
• Testimonials
• Plugin development
  • General
  • Adding support for new LLMs
• About the developer

Features

• Suggested changes are inserted directly into the text: Additions as ==highlights== and removals as ~~strikethroughs~~.
• Accept or reject changes with just one hotkey.
• Easy to use: No complicated plugin settings and AI parameters to configure.

	Professional proofreading service	Proofreader plugin
Cost for English text of 10,000 words	~ $400, depending on the service	~ $0.01 – $0.061
Completion duration	up to 3 work days	about 5 minutes
Input format	usually Microsoft Word (.docx)	Markdown file in Obsidian
Method of incorporating changes	mostly mouse clicks	keyboard shortcuts
Additional benefits	Editor makes general comments on writing style.	Plugin can also be used to quickly proofread single sentences or paragraphs.

[!NOTE] This plugin requires an API key from one of the supported providers (OpenAI, Google, Mistral, or OpenRouter) and incurs costs based on usage. Network requests are made when running the proofreading command. (PRs adding support for other LLMs are welcome.)

Installation & setup

Plugin installation

Install in Obsidian

Get an API key

OpenAI

1. Create an OpenAI account.
2. Go to this site, and click Create new secret key.
3. Copy the API key.
4. In Obsidian, go to Settings → Proofreader → OpenAI and paste your API key there.

[!TIP] The usage costs should not be very high, nonetheless you can track them on this page.

Google

1. Create a Google account if you don't have one.
2. Go to Google AI Studio and click Create API key.
3. Copy the API key.
4. In Obsidian, go to Settings → Proofreader → Google and paste your API key there.

Mistral

1. Create a Mistral account.
2. Go to API keys and click Create new key.
3. Copy the API key.
4. In Obsidian, go to Settings → Proofreader → Mistral and paste your API key there.

OpenRouter

1. Create an OpenRouter account.
2. Go to API keys and click Create key.
3. Copy the API key.
4. In Obsidian, go to Settings → Proofreader → OpenRouter and paste your API key there.

Usage

1. Use the command Proofread selection/paragraph to check the selected text. If there is no selection, the command will check the current paragraph. Alternatively, you can also check the whole document with Proofread full document. However, note that the quality of AI suggestions tends to decrease when proofreading too much text at once.
2. The changes are automatically inserted.
3. Accept/reject changes with Accept suggestions in selection/paragraph and Reject suggestions in selection/paragraph. Same as the proofreading command, the accept and reject commands affect the current paragraph if there is no selection. Alternatively, you can also only accept/reject the next suggestion after your cursor via Accept next suggestion and Reject next suggestion.

Visual appearance of the changes

You can add the following CSS snippet to make highlights and strikethroughs appear like suggested changes, similar to the screenshot further above. (Manual: How to add CSS snippets.)

.cm-strikethrough {
	text-decoration-color: var(--color-red);
}

.cm-s-obsidian span.cm-highlight {
	background-color: rgba(var(--color-green-rgb), 35%);
}

Testimonials

I was paying $29 a month for type.ai until today, your plugin made me cancel the subscription, because the only feature I wanted from there was this inline granular diffing which no other app offered, until Proofreader. @samwega

Plugin development

General

just init   # run once after cloning

just format # run all formatters
just build  # builds the plugin
just check  # runs the pre-commit hook (without committing)

[!NOTE] This repo uses a pre-commit hook, which prevents commits that do not build or do not pass the checks.

Adding support for new LLMs

1. Create a new adapter for the LLM in ./src/providers/. This should take ~50 lines of code.
2. In ./src/providers/model-info.ts, add the adapter function to PROVIDER_REQUEST_MAP, and add models for the new provider to MODEL_SPECS.
3. In ./src/settings.ts, add a setting for the API key to ProofreaderSettingsMenu and add a field to DEFAULT_SETTINGS.

About the developer

In my day job, I am a sociologist studying the social mechanisms underlying the digital economy. For my PhD project, I investigate the governance of the app economy and how software ecosystems manage the tension between innovation and compatibility. If you are interested in this subject, feel free to get in touch.

• Website
• ResearchGate
• Mastodon
• LinkedIn

If you find this project helpful, you can support me via 🩷 GitHub Sponsors.

Footnotes

1. Estimated pricing for the GPT 4.1 nano model in April 2025. The plugin developer is not responsible if the actual costs differ. You can track your usage costs on this page. ↩