---
title: "Content delivery optimization"
sidebar_label: "Content delivery optimization"
description: "What types of content delivery optimization are available, how to choose an optimization type"
sidebar_position: 6
---

import Formbricks from '@theme/MDXComponents/Formbricks'

# Content delivery optimization

When [creating a resource](/cdn/create-resource.mdx), you choose the content delivery optimization type. [The optimization type](#optimization-types) determines how the CDN processes content: optimizes the delivery of images, video, and text formats or delivers large files in parts (slices). After creating a resource, you can [change the content delivery optimization type](#change-optimization-type).

If you selected the Large files type when creating the resource, you can [change the slice size](#change-slice-size).

## Optimization types \{#optimization-types}

### Static \{#static-files}

The Static type is intended for optimizing the delivery of small files: images, video and audio files, and text formats.

Optimal parameters are used to process images and videos and cannot be managed. To manage image quality and format yourself (for example, to convert to WebP), you can enable the [Image Optimization](/cdn/content/image-optimization.mdx) service.

For processing text formats, such as `HTML`, `CSS`, `JS`, `JSON`, `XML`, `SVG`, the [Gzip compression algorithm](/cdn/content/file-compression-algorithms.mdx#gzip) is used. Additionally, you can enable the [Brotli compression algorithm](/cdn/content/file-compression-algorithms.mdx#brotli).

### Large files \{#large-files}

The Large files type is intended for processing files larger than 20 MB. These files are cached and delivered in parts (slices) using HTTP Range requests. By default, the slice size is 16 MB. You can [change the slice size](#change-slice-size) manually.

## Change content delivery optimization type \{#change-optimization-type}

1. In the [control panel](https://my.selectel.ru/cdn-v3), on the top menu, click **Products** and select **CDN**.

2. In the **CDN Resources** section, open the resource page → **Optimization** tab.

3. In the **Delivery optimization type** block, select the [optimization type](#optimization-types):

   * Static — suitable for delivering small files: images, video and audio files, text formats;
   * or Large files — suitable for delivering large files without loss of quality, for example, video. Files are cached and delivered in slices using HTTP Range requests.

4. Optional: if you selected the Large files type, you can change the slice size:

   4.1. Select the **Specify slice size manually** checkbox.

   4.2. Specify the slice size. Available values: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 MB.

5. Click **Apply**. While the settings are being applied, the resource will have the `PROCESSING` status. You cannot apply other settings during this time. The settings will be applied once the resource switches to the `ACTIVE`.

6. [Clear the cache](/cdn/content/cleanup-cache.mdx).

## Change slice size \{#change-slice-size}

1. In the [control panel](https://my.selectel.ru/cdn-v3), on the top menu, click **Products** and select **CDN**.

2. In the **CDN Resources** section, open the resource page → **Optimization** tab.

3. Ensure that the Large files type is selected in the **Delivery optimization type** block.

4. Select the **Specify slice size manually** checkbox.

5. Specify the slice size. Available values: 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 MB.

6. Click **Apply**. While the settings are being applied, the resource will have the `PROCESSING` status. You cannot apply other settings during this time. The settings will be applied once the resource switches to the `ACTIVE`.

7. [Clear the cache](/cdn/content/cleanup-cache.mdx).

<Formbricks />