How to Fix Grammar with OpenAI on Mac
Use OpenAI's advanced language models to instantly fix grammar, spelling, and punctuation errors in any Mac app. Echoo sends your selected text to OpenAI and replaces it with a polished version in seconds.
Why This Combination Works
OpenAI's GPT models are trained on vast amounts of well-edited English text, making them exceptionally accurate at catching subtle grammar mistakes, awkward phrasing, and inconsistent punctuation. GPT-4o in particular excels at preserving your original tone while correcting errors, avoiding the robotic rewrites that simpler tools produce. The low latency of OpenAI's API means corrections appear almost instantly after you trigger the shortcut.
Recommended Model
GPT-4o is the best choice for grammar fixing. It delivers near-perfect accuracy on complex grammar rules like subjunctive mood, comma splices, and dangling modifiers while responding in under two seconds. For lighter editing on shorter text, GPT-4o Mini offers comparable quality at a fraction of the cost.
Example Prompt
Fix all grammar, spelling, and punctuation errors in the following text. Preserve the original meaning, tone, and formatting. Do not rewrite sentences unless grammatically necessary. Return only the corrected text.
Setup Steps
Download Echoo
Install Echoo from echoo.ai. It runs in your Mac menu bar and works across every app.
Add your OpenAI API key
Open Echoo settings, go to the Providers tab, select OpenAI, and paste your API key from platform.openai.com.
Select the Fix Grammar command
Echoo includes a built-in Fix Grammar command. Choose GPT-4o as the model in your command settings for the best results.
Highlight text and press the shortcut
Select the text you want to fix in any app, press your assigned keyboard shortcut, and Echoo will replace it with the corrected version.
Frequently Asked Questions
GPT-4o costs roughly $2.50 per million input tokens. A typical grammar correction of a few paragraphs costs a fraction of a cent — far cheaper than a monthly Grammarly subscription for similar quality.
No. Echoo's grammar prompt explicitly instructs the model to preserve your original meaning and tone. Only grammatical errors, misspellings, and punctuation issues are corrected.
Yes, in most cases. Because Echoo sends the full text in one request and receives the corrected version back, corrections happen in one to two seconds regardless of text length, without waiting for inline suggestions to load.
Explore More
Ready to Try It?
Download Echoo for free and start transforming text with AI shortcuts.