---
metadata:
  - name: generator
    content: Diplodoc Platform v5.57.4
alternate:
  - https://yandex.com/support/metrica/en/webvisor/requirements.md
  - https://yandex.com/support/metrica/es/webvisor/requirements.md
  - https://yandex.com/support/metrica/pt/webvisor/requirements.md
  - https://yandex.com/support/metrica/ru/webvisor/requirements.md
  - https://yandex.com/support/metrica/tr/webvisor/requirements.md
  - https://yandex.com/support/metrica/zh/webvisor/requirements.md
  - href: https://yandex.com/support/metrica/en/webvisor/requirements.md
    type: text/markdown
    title: Markdown version
  - href: https://yandex.com/support/metrica/en/llms.txt
    rel: describedby
title: Requirements and restrictions for Session Replay
description: Requirements and restrictions for Session Replay.
---
> **Documentation Index:** Fetch the complete configuration index at https://yandex.com/support/metrica/en/llms.txt


# Requirements and restrictions for Session Replay


{% note info %}

When you view a recording, its content may differ from what the site looks like at the moment. This is because Session Replay captures the site’s HTML content at the time of the session, not when you’re viewing the recording.

{% endnote %}

**Content-Type options**

 
:   Session Replay supports style, image, and font files, as well as other elements with a specific `Content-Type` type:

   <div class="table-without-border">

   #|
   || `text/css`

   `image/`

   `jpg`

   `font/ttf`

   `font/otf`

   `font/opentype`

   `font/truetype`

   | `font/woff`

   `font/woff2`

   `application/font-otf`

   `application/font-ttf`

   `application/font-sfnt`

   `application/x-font-ttf`

   `application/font-woff`

   | `application/font-woff2`

   `application/vnd.ms-fontobject`

   `application/font-truetype`

   `application/font-opentype`

   `application/octet-stream`

   `text/html`

   `text/plain` ||
   |#

   </div>

   Elements with a different `Content-Type` type may be displayed incorrectly in session recordings.

**Robot sessions**

 
:   Session Replay can also record sessions that Yandex Metrica or Yandex Direct identify as robot traffic.

**Recording video and audio content**

 
:   Session Replay doesn't record the content of HTML `audio` and `video` elements and how the user interacts with them, if the `Audio` and `Video` objects are modified inside these elements.

**Recording browser tabs in private browsing mode**

 
:   Due to browser limitations, Session Replay may incorrectly record information about tabs in private mode (for example, [Incognito](https://yandex.com/support/browser/personal-data-protection/incognito-mode.html) in Yandex Browser or similar modes in other browsers).

   Some browsers may block the tag entirely in private mode, which means that the session won't be recorded and won't appear in your statistics.

**Recording iframe contents from another domain**

 
:   For Session Replay to record iframe contents where the address differs from the site address, configure the tag in a [specific way](https://yandex.com/support/metrica/en/webvisor/iframe-support.md#domains-dont-match).

**Recording and playback of pages with layout errors** {#5}

 
:   Session Replay records pages exactly as the browser displays them. This means any HTML layout defects (like unclosed tags or incorrect element nesting) will be reproduced in the recording just as the browser processed them.

   Session Replay typically adapts to such errors. But if the page layout doesn't comply with [W3C standards](https://www.w3.org/standards/) or contains numerous defects, the session recording may not look the way the site owner expects.

**Recording pages with flexible layout** {#3}

 
:   Sessions on pages with flexible layouts will be replayed correctly, even if the resolution of the user’s screen is not the same as the replay screen. During playback, you might see small cursor jumps due to different relative positioning of elements on the recorded and replayed pages.

**Using Session Replay 2.0 for frequently updated CSS files** {#css}

 
:   If your site frequently updates CSS, add the content hash to the style file names. This will make the file name change every time you update its contents. For example, `style.390b32d4d49d5e7d.css` will become `style.0c573d460df87d4de5a4.css`. This lets Session Replay use the style that the site visitor sees when it records a session.

**Using Session Replay if the site has multiple tags** {#2}

 
:   In this case, enable Session Replay on just one of the installed tags. If Session Replay is enabled for all tags, the data for all tags is recorded incorrectly.

**Limit on number of recordings per day** {#4}

 
:   In a single day, Session Replay records a sufficient number of sessions to form a representative sample. The number of sessions recorded throughout the day is determined by a special algorithm and may vary.

**Limit on period for storing recordings**

 
:   Data is stored for 15 days, including the current day.

**Processing styles**

 
:   If the site uses [runtime styles](*рантайм-стили) (including from the Data Styled Components series), Session Replay does not record sessions or records them incorrectly. We recommend using classic styles.

**Support for Shadow DOM**

 
:   Session Replay does not support Shadow DOM technologies.

**Browser support**

 
:   Session Replay supports session recordings for most modern desktop browsers, including Yandex Browser, Google Chrome, Firefox, Safari, Opera, and Microsoft Edge. There is limited support for recording in beta versions and in certain mobile browsers. There is also limited support for session recording and playback in Internet Explorer (any version).
    
    Different browsers may process the same page in different ways. This means that to accurately replay a session, you should use the same browser as it was originally recorded in.

**Canvas support** {#iframe-canvas}

 
:   Session Replay doesn’t record site content if it is displayed using the [canvas](https://www.w3.org/TR/html5/semantics-scripting.html#the-canvas-element) element.

**Recommended site encoding** {#1}

 
:   Session Replay correctly records user actions if the site uses [UTF-8 encoding](https://en.wikipedia.org/wiki/UTF-8).

<!-- source: en/_includes/buttons/chat-button.md -->
[Chat with us](https://yandex.com/chat/#/user/036e6a02-3620-9cdc-4c5e-a34667a7379e?utm_source=spravka){.button}

<!-- source: en/_includes/styles/href-to-button.md -->

<!-- endsource: en/_includes/styles/href-to-button.md -->
<!-- endsource: en/_includes/buttons/chat-button.md -->

<!-- source: en/_includes/popup/id-qanda/feedback-intro.md -->
<div class="cut-button">

{% cut "Write an email" %}

Select a question to find a solution.

{% list tabs radio %}

- Incorrect site content was recorded

  The page content in the recording may be different from the actual content. It’s likely that the CSS on the site frequently changes. In this case, add the content hash to the style file names. This will make the file name change every time you update its contents. For example, `style.390b32d4d49d5e7d.css` will become `style.0c573d460df87d4de5a4.css`. This lets Session Replay use the style that the site visitor sees when it records a session.

- Error during playback

  Do the following:

  - [Clear the](https://yandex.ru/support/browser/personal-data-protection/cache-memory.html?lang=ru#clearing-cache) browser cache.
  - Disable all plugins and browser extensions.
  - [Delete the browser cookies](https://yandex.ru/support/browser/personal-data-protection/cookies.html#del-cookie).
  - Check the firewall settings. It’s possible that the firewall is blocking the Yandex Metrica tag script. The tag could also be blocked by the [Adblock Plus](https://adblockplus.org) extension.

  {% cut "I followed the recommendations, but the error persists" %}


  <div style="padding: 15px;
       margin: 10px 0;
       background: #FFFFFF;
       border-radius: 10px;
       border: 1px solid var(--g-color-line-generic);">
    <iframe style="background: #FFFFFF;"
          height="700"
          width="100%"
          frameborder="0"
          src="https://forms.yandex.com/surveys/1711/?&iframe=1&lang=en">
    </iframe>
  </div>

  {% endcut %}

- Other questions

  
  If you have more questions about Session Replay, submit them in the form below. Provide an example of a session with incorrectly displayed data and specify the full version of your browser.

  <div style="padding: 15px;
       margin: 10px 0;
       background: #FFFFFF;
       border-radius: 10px;
       border: 1px solid var(--g-color-line-generic);">
    <iframe style="background: #FFFFFF;"
          height="700"
          width="100%"
          frameborder="0"
          src="https://forms.yandex.com/surveys/1711/?&iframe=1&lang=en">
    </iframe>
  </div>

{% endlist %}

{% endcut %}

</div>

<!-- source: en/_includes/styles/cut-button.md -->

<!-- endsource: en/_includes/styles/cut-button.md -->
<!-- endsource: en/_includes/popup/id-qanda/feedback-intro.md -->


<!-- source: en/_includes/footer-links.md -->
- - -

<div class="borderless-table">

#|
||
Useful links

- [Demo tag](https://metrica.yandex.com/r/dashboard?)
- [Add a tag](https://metrica.yandex.com/add/)
- [Free tag setup](https://yandex.com/promo/freeservice/metrica?utm_source=help_metrica_en&utm_medium=cpc&utm_campaign=1)
- [Yandex Metrica API](https://tech.yandex.com/metrika/)
- [Suggest your idea](https://yandex.com/support/metrica/troubleshooting/idea.html)
- [Discuss in Telegram](https://t.me/yandexmetrika)
|
Online training

- [Get a Yandex Metrica certificate](https://yandex.ru/adv/expert/exam/metrika/?utm_source=metrika_help&utm_medium=web&utm_campaign=static&utm_content=useful_links)


- [Take a training course](https://yandex.com/adv/edu/online/metrika?utm_source=metrika_help&utm_medium=web&utm_campaign=static&utm_content=useful_links)

||
|#

</div>

<!-- source: en/_includes/styles/table-style.md -->

<!-- endsource: en/_includes/styles/table-style.md -->
<!-- endsource: en/_includes/footer-links.md -->

<!-- source: en/_includes/styles/cut-button.md -->

<!-- endsource: en/_includes/styles/cut-button.md -->

<!-- source: en/_includes/styles/href-to-button.md -->

<!-- endsource: en/_includes/styles/href-to-button.md -->

<!-- source: en/_includes/styles/table-without-border.md -->

<!-- endsource: en/_includes/styles/table-without-border.md -->

[*рантайм-стили]: Styles that are generated when the page loads.