> ## Documentation Index
> Fetch the complete documentation index at: https://docs.modelslab.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Rate Limits

> Understanding ModelsLab API rate limits, request queuing, and concurrency limits for Free, Starter, Pro, and Enterprise subscription plans.

<Info>
  **Rate limits help ensure fair usage and optimal performance for all users. Each subscription plan has specific limits for queued API requests.**
</Info>

## Request Queue Limits

Our API uses request queue limits to manage server load and ensure optimal performance. The limits vary based on your subscription plan:

<CardGroup>
  <Card title="Pay as you go plan" icon="dollar-sign">
    **5 queued API requests**

    Perfect for individual developers and small projects getting started with our APIs.
  </Card>

  <Card title="Standard plan" icon="star">
    **10 queued API requests**

    Ideal for growing businesses and applications with moderate usage requirements.
  </Card>

  <Card title="Unlimited Premium Plan" icon="crown">
    **15 queued API requests**

    Designed for enterprise applications and high-volume usage scenarios.
  </Card>
</CardGroup>

## How Request Queuing Works

Request queuing ensures that API calls are processed sequentially in a controlled manner. Here's what you need to know:

### Understanding the Limits

* **Sequential Processing**: Requests are processed one after another in queue order
* **Queue Management**: New requests are added to the queue and processed when previous ones complete
* **Per Account**: Limits apply to your entire account, not per API endpoint
* **Real-time**: The limit is enforced in real-time as requests come in

### Example Scenarios

<AccordionGroup>
  <Accordion title="Pay as you go (5 queued requests)">
    If you have 5 requests in the queue and try to make a 6th request, it will be rejected until one of the queued requests completes and is processed.
  </Accordion>

  <Accordion title="Standard plan (10 queued requests)">
    You can have up to 10 requests in the queue. Any additional requests will be rejected until queue space becomes available.
  </Accordion>

  <Accordion title="Premium plan (15 queued requests)">
    Up to 15 requests can be queued, providing the highest capacity for enterprise applications.
  </Accordion>
</AccordionGroup>

## Request Queuing

When you reach your queue limit:

1. **Queue Full**: Additional requests are rejected with a rate limit error
2. **Sequential Processing**: Requests are processed one after another in queue order
3. **FIFO Order**: Requests are processed in First-In-First-Out order
4. **Automatic Processing**: Queued requests are automatically processed as previous ones complete

## Best Practices

### Optimizing for Rate Limits

<Steps>
  <Step title="Monitor Your Queue">
    Keep track of your queued requests to avoid hitting limits unexpectedly.
  </Step>

  <Step title="Implement Retry Logic">
    Add exponential backoff retry logic for better handling of rate limit scenarios.
  </Step>

  <Step title="Batch Operations">
    When possible, combine multiple operations into single requests to reduce queue usage.
  </Step>

  <Step title="Upgrade When Needed">
    Consider upgrading your plan if you consistently hit queue limits.
  </Step>
</Steps>

### Error Handling

When you hit rate limits, you'll receive an HTTP 429 status code with details about the limit:

```json json theme={null}
{
  "status": "error",
  "message": "Rate limit exceeded. Maximum 5 queued requests allowed.",
  "retry_after": 30
}
```

## Upgrading Your Plan

If you need higher queue limits:

1. **Log in** to your ModelsLab account
2. **Navigate** to the billing section
3. **Select** a higher tier plan
4. **New limits** take effect immediately

<Note>
  **Need more than 15 queued requests?** Contact our enterprise team for custom solutions tailored to your specific needs.
</Note>

## Frequently Asked Questions

<AccordionGroup>
  <Accordion title="What happens if I exceed my queue limit?">
    Additional requests are rejected with a rate limit error. You'll need to wait for queued requests to complete before making new ones.
  </Accordion>

  <Accordion title="Do rate limits reset daily?">
    No, queue limits are enforced in real-time, not on a daily basis. They're based on current queue size, not total requests per day.
  </Accordion>

  <Accordion title="Are there different limits for different APIs?">
    No, the queue limit applies to your entire account across all API endpoints.
  </Accordion>
</AccordionGroup>

## Support

Need help with rate limits or want to discuss custom solutions?

* **Documentation**: Check our [API Reference](/api-reference) for detailed endpoint information
* **Support**: Contact us at [support@modelslab.com](mailto:support@modelslab.com)
* **Discord**: Join our [Discord community](https://discord.com/invite/modelslab-1033301189254729748) for real-time help