What you install
- Refine
- A macOS writing assistant
- LanguageTool
- A Java HTTP server and a compatible client
See the separate hosted LanguageTool comparison
Refine vs Self-hosted LanguageTool
A Mac writing assistant or a grammar server?
Refine works across most Mac apps. Self-hosted LanguageTool provides a rule-based HTTP server that you connect to a compatible client.
v1.34
macOS 14+
Full-featured 7-day free trial
Quick comparison
| Feature | Refine with local model | LanguageTool |
|---|---|---|
| What you install | A macOS writing assistant | A Java HTTP server and a compatible client |
| Checking approach | Contextual local language model | Deterministic grammar and spelling rules |
| Across Mac apps | Available across most Mac apps | Not system-wide checking by itself |
| Software price | $38 one-time lifetime license | LGPL open-source core; hosting and administration can still have costs |
Checking approach
- Refine
- Contextual local language model
- LanguageTool
- Deterministic grammar and spelling rules
Across Mac apps
- Refine
- Available across most Mac apps
- LanguageTool
- Not system-wide checking by itself
Software price
- Refine
- $38 one-time lifetime license
- LanguageTool
- LGPL open-source core; hosting and administration can still have costs
Detailed feature comparison
The products solve different parts of the writing workflow. One is an end-user Mac app, while the other is a server API that needs a client and administration.
Product form
Refine
A Mac app with checking available across most applications.
LanguageTool
An HTTP server and API, not system-wide checking by itself.
Where checks run
Refine
On your Mac with a downloaded language model.
LanguageTool
On the server you operate. Writing stays on the same device only when the server also runs on that same device.
Writing destination
Refine
Checked text is not uploaded to Refine servers.
LanguageTool
The client sends writing to the server you operate, so the server location defines the privacy boundary.
Grammar approach
Refine
Context-aware grammar, spelling, and fluency corrections from a local language model.
LanguageTool
Grammar, spelling, punctuation, and style findings from the open-source rule-based engine.
Included capabilities
Refine
Explanations, translation, custom prompts, and broader writing changes.
LanguageTool
The basic server does not include cloud-only AI rules, the Premium service, or commercial hosted features.
Setup and operation
Refine
Install the app and download a supported local model.
LanguageTool
Requires Java, server setup, a compatible client, and user-managed updates and security.
Language coverage
Refine
More than 50 languages and regional variants.
LanguageTool
Language coverage provided by the installed open-source core and its rule packages.
Price and license
Refine
$38 once for one Mac, or $68 once for 3 Macs.
LanguageTool
The core uses the LGPL. Infrastructure, client integration, maintenance, hosting, and administration can still have costs.
Limits of fixed rule coverage
Where rule-based checking can leave an error unchanged
These same-input checks show particular American-English corrections that depend on more than the rule-based server returned.
Selected American-English examples, run locally on the versions shown. For each example, both tools received the same input and the result was compared with the expected minimal correction. They illustrate particular rules and are not an overall accuracy ranking.
Refine v1.34 with Gemma 4 E2B and LanguageTool self-hosted v6.8.
What the local check showed
With the same input, the language-model output matched the expected minimal correction. The rule-based checker supplied no valid correction.
Preposition before a destination
When “arrive” names a destination, English normally introduces that destination with a preposition such as “at.”
Text to check
The delivery truck arrived the warehouse before dawn.
Expected change
Language model: Caught
Changed “arrived the warehouse” to “arrived at the warehouse.”
Rule-based checker: Missed
No valid correction; the error stayed unchanged.
Do-support in a direct question
A direct “why” question with an ordinary verb needs “did” before the subject, with the main verb in its base form.
Text to check
Why the meeting ended early?
Expected change
Language model: Caught
Changed “Why the meeting ended” to “Why did the meeting end.”
Rule-based checker: Missed
No valid correction; the error stayed unchanged.
Past tense of “write”
The time word “yesterday” calls for the finite past form “wrote.” “Written” is a participle and cannot stand alone as the finite verb here.
Text to check
The clerk written the final note yesterday.
Expected change
Language model: Caught
Changed “written” to “wrote.”
Rule-based checker: Missed
No valid correction; the error stayed unchanged.
Negating an infinitive
To negate this infinitive, “not” belongs before “to.” The finite form “don’t” cannot fill that position.
Text to check
The host asked us to don't open the side door.
Expected change
Language model: Caught
Changed “to don't” to “not to.”
Rule-based checker: Missed
No valid correction; the error stayed unchanged.
Which option fits your workflow?
Choose Refine for an integrated Mac writing assistant
Refine fits when you want contextual local writing help without operating a grammar server.
- You want grammar, fluency, explanations, translation, and custom prompts in one app.
- You need writing support across multiple languages and regional variants.
- You want checking across most Mac apps without connecting a separate client to a server.
Choose self-hosted LanguageTool for a rule-based API
The self-hosted server fits when you want to operate the open-source grammar core and connect it to your own software.
- You prefer deterministic rules and API responses over a language model.
- You can provide Java, a compatible client, monitoring, updates, and security.
- You accept that the basic server does not include cloud-only AI rules, Premium service, or commercial hosted features.
Refine vs Self-hosted LanguageTool FAQ
Is self-hosted LanguageTool a complete writing app?
No. The basic self-hosted product is an HTTP server and API. It needs a compatible client and does not provide system-wide checking by itself.
Does self-hosted LanguageTool keep writing on my device?
The client sends writing to the server you operate. Writing stays on the same device only when that server runs on the same device. A server on another computer receives the text there.
What do I manage when I self-host LanguageTool?
You manage Java, server setup, a compatible client, availability, updates, and security.
Does the self-hosted server include every LanguageTool feature?
No. The open-source basic server does not include LanguageTool's cloud-only AI rules, Premium service, or commercial hosted features.
Is self-hosted LanguageTool free?
The open-source core uses the LGPL, but infrastructure, client integration, maintenance, hosting, and administration can still have costs.
Source notes
Self-hosted LanguageTool details were reviewed July 30, 2026. Product features can change after review.
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Try contextual writing help on your Mac
Download Refine and use the full-featured trial before buying a lifetime license.
v1.34
macOS 14+
Full-featured 7-day free trial