# Grammar Checker API

> Grammar Checker API for grammar, spelling, sentence structure, tone, and mechanics suggestions that improve writing without triggering AI detection.

Empower error-free writing with our [grammar checker](https://copyleaks.com/grammar-checker), offering suggestions on grammar, sentence structure, tone, overall mechanics, and more.

![Grammar Checker API](/assets/mainpage/Absolute-Confidence.png)

## Why Grammar Checker Matters

Good writing is essential for communication, but even the best writers make mistakes. With deadlines and pressure, catching every error becomes nearly impossible:

- **Professional Credibility**: Grammar mistakes can undermine your expertise and damage your reputation
- **Clear Communication**: Poor sentence structure confuses readers and weakens your message
- **Time Pressure**: Manual proofreading takes time you don't have, especially with large volumes of content
- **Consistency Issues**: Different writers have different styles, making content feel disjointed
- **Language Barriers**: Non-native speakers need extra support to write confidently in other languages
- **Writing Development**: It's not just about fixing mistakes - it's about learning and growing. Our assistant helps writers develop their skills over time with constructive feedback that teaches better writing habits

Traditional grammar checkers miss context and nuance, leading to suggestions that don't fit your writing style or audience. You need assistance that actually understands what you're trying to say and helps you grow as a writer.

## Core Capabilities

<CardGroup cols={2}>
    <Card title="Fix Grammar and Mechanics" icon="spell-check">
      Catch spelling mistakes, comma errors, subject-verb disagreements, and everything in between with comprehensive grammar checking.
    </Card>
    <Card title="Improve Sentence Structure" icon="pen-to-square">
      Get suggestions to prevent run-ons, fragments, and awkward phrasing that make your writing hard to follow.
    </Card>
    <Card title="Choose Better Words" icon="book-open">
      Receive vocabulary suggestions that match your audience and catch potentially misused words and homophones.
    </Card>
    <Card title="Supports Multiple Languages" icon="language">
      Get Grammar Checker in English, German, Spanish, French, Italian and Portuguese.
    </Card>
</CardGroup>

## Features

Our Grammar Checker goes beyond basic spell-check to help you communicate clearly and confidently.

### Grammar Score - Complete Writing Assessment

Get a comprehensive evaluation of your writing with our Grammar Score, which breaks down your content into four key areas:

- **Corrections**: Grammar, mechanics, sentence structure, and word choice suggestions
- **Insights**: Analysis of word length, sentence length, reading time, and writing patterns
- **Readability**: How easy your content is to read, with historical data for comparison
- **Progress Tracking**: See how your writing improves over time

[**Learn more**](/reference/data-types/writing/writing-assistant)

### Assess Writing Quality in Multiple Languages

Break down language barriers with Grammar Checker that actually understands different languages. We provide native-level support for English, German, Spanish, French, Italian, and Portuguese - each with its own specialized grammar engine, not just English rules translated. This means more accurate suggestions that sound natural to native speakers.

[**Learn more**](/reference/actions/writing-assistant/check)

### Comprehensive Error Detection

Our Grammar Checker detects more than 30 different types of writing issues, each with a specific correction suggestion to help you improve. Every detected error comes with its type and a tailored fix:

- **Grammar Issues** - Subject-verb disagreements, verb forms, articles, prepositions, pronouns, conjunctions, and more
- **Sentence Structure** - Run-on sentences, fragments, comma splices, missing or extra words, and clarity improvements  
- **Word Choice** - Misused words, homophones (like "their" vs "there"), and vocabulary suggestions
- **Mechanics** - Spelling, punctuation, capitalization, hyphen usage, spacing, and accent marks

Each correction is categorized so you understand what type of issue was found and why the suggestion helps. This isn't just about catching mistakes - it's about learning patterns that make you a better writer over time.

[**Learn more**](/reference/data-types/writing/correction-types)

![Grammar Checker API](/assets/mainpage/PersonalProofreader.png)

### Work With Any Document Type

Don't worry about file formats - our Grammar Checker works with virtually any document type. We support Office documents (Word, PowerPoint, Excel), PDFs with OCR processing, text files, HTML content, and academic formats like LaTeX. 

Simply upload your document and get comprehensive writing feedback while preserving the original structure.

[**Learn more**](/reference/actions/authenticity/submit-file)

## Use Cases

<Tabs>
  <Tab title="Educational Institutions">
    Help students improve their writing skills without triggering [AI detection](https://copyleaks.com/ai-detector). Perfect for essays, research papers, and assignments.
    
    [**Learn more**](/concepts/use-cases/academic-integrity)
  </Tab>
  <Tab title="Publishers">
    Ensure articles and content are error-free before publication. Maintain consistent quality across multiple writers and editors.
    
    [**Learn more**](/concepts/use-cases/publishers)
  </Tab>
</Tabs>

## Works Better Together

Our Grammar Checker works great with our other tools to give you complete content confidence.

<CardGroup cols={2}>
  <Card title="AI Detector" icon="robot" href="/concepts/products/ai-text-detection-api">Make sure your improved writing still reads as human-written, not AI-generated</Card>
  <Card title="Plagiarism Checker" icon="magnifying-glass" href="/concepts/products/plagiarism-checker-api">Ensure your polished writing is also completely original and properly cited</Card>
</CardGroup>

![Proofreader](/assets/mainpage/Fully-Transparent.png)

## Next Steps

Ready to empower error-free writing in your application?

<CardGroup cols={2}>
  <Card title="Start Building" icon="rocket" href="/guides/writing/check-grammar">Follow our simple guide to add Grammar Checker to your application</Card>
  <Card title="API Documentation" icon="code" href="/reference/actions/writing-assistant/check">See all the technical details for our Grammar Checker API</Card>
  <Card title="Correction Types" icon="list-check" href="/reference/actions/writing-assistant/correction-types">Learn about all available correction types and writing suggestions</Card>
</CardGroup>

<Card title="Want to See It in Action?" icon="calendar-check" href="https://copyleaks.com/book-a-demo" cta="Book a Demo" arrow="true">
  Get a personalized demo and see how easy it is to add intelligent Grammar Checker to your platform. We'll show you the Grammar Score and help you choose the right language support for your needs.
</Card>