---
name: natural-language-understanding-usage-limits
title: Usage limits
description: The following usage limits and restrictions apply to Natural Language Understanding service instances.
last-updated: 2022-08-05
---

> ## Documentation Index
> The table of contents for this documentation set is at https://cloud.ibm.com/docs/natural-language-understanding?format=markdown
> The index for all IBM Cloud docs is at: https://cloud.ibm.com/docs/llms.txt
> Use these files to discover more information as needed.

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# Usage limits
{: #usage-limits}

The following usage limits and restrictions apply to Natural Language Understanding service instances.
{: shortdesc}

## Analyzed text limit
{: #analyzed-text}

Natural Language Understanding truncates analyzed text that contains more than 50,000 single-byte or multibyte characters. To view the text that counts toward this limit in your requests, set the `return_analyzed_text` parameter to `true`.

You can set a smaller character limit with the `limit_text_characters` parameter. If you are interested in analyzing only a small portion of your content, this can help you avoid excessive costs.

Example parameters object:
```json
{
  "url": "ibm.com",
  "limit_text_characters": 10000,
  "return_analyzed_text": true,
  "features": {
    "concepts": {}
  }
}
```

## Request limit
{: #concurrent-requests}

Each Natural Language Understanding service instance is limited, based on the number of analyze requests being processed. For the Lite plan, the limit is 5 analyze requests per second; for the Standard plan, the limit is 150 analyze requests per second. Analyze requests exceeding these limits may receive a `429: Too Many Requests` error.

The limit for the Standard plan can be increased by [opening a support ticket](https://ibm.biz/ibmcloudsupport).

All other requests are rate-limited at 5 requests per second.

## Custom model training limit
{: custom-model-training-limit}

The maximum number of models that can be trained via the Natural Language Understanding customization API in parallel is 3.

## Custom model size limit for Lite pricing plans
{: #custom-models}

There is a size limit for Knowledge Studio custom models that are deployed to Natural Language Understanding service instances on Lite pricing plans. To remove the custom model size limit, upgrade your Natural Language Understanding service instance to a paid pricing plan. You can find your service instances on the IBM Cloud [resources page](https://cloud.ibm.com/resources).

## Language support
{: #usage-language-support}

Different language restrictions apply depending on how you use the service. For details, see the [Language support](https://cloud.ibm.com/docs/natural-language-understanding?topic=natural-language-understanding-language-support&format=markdown) page.