title: Toggle/Disable real-time Markdown preview update in VSCode?
body: <p>I am using VSCode to edit Markdown files with the formatted preview to the side.  Every time I edit a file, the preview updates.  For long files full of TeX math, this can significantly slow down the editor.  Is there a way to disable real-time updating, or only update on save?</p>
  <p><strong>Update</strong>: This doesn't appear to be possible in VSCode at the moment, even with an extension (see here: <a href="https://github.com/yzhang-gh/vscode-markdown/issues/991" rel="nofollow noreferrer">https://github.com/yzhang-gh/vscode-markdown/issues/991</a>).</p>
  <p>I've opened a feature request which is pending community review here:</p>
  <p><a href="https://github.com/microsoft/vscode/issues/129252" rel="nofollow noreferrer">https://github.com/microsoft/vscode/issues/129252</a></p>
  <p><strong>Update</strong>: The best solution I've found is to open a new Markdown file, do most of the editing there, and then paste it back into the main file.</p>
  <p><strong>Update</strong>: It turns out part of the slowness was having both the new built-in KaTex math renderer and an extension to do this running at the same time...  This also seems to be why the preview would appear to refresh twice at times.</p>
  <p>I've been using the Markdown All in One extension to render KaTex math.
  Recently, the June 2021 update (1.58) introduced built-in KaTeX math rendering with the extension &quot;Markdown Math&quot; (which can be found in the Extensions tab and searching for <code>@builtin</code>).</p>
  <p>Running both math renderers at the same time seems to cause issues:</p>
  <p><a href="https://markdown-all-in-one.github.io/docs/guide/compatibility.html#rendering-for-math-in-the-markdown-preview" rel="nofollow noreferrer">https://markdown-all-in-one.github.io/docs/guide/compatibility.html#rendering-for-math-in-the-markdown-preview</a></p>
  <p><a href="https://github.com/yzhang-gh/vscode-markdown/issues/1010" rel="nofollow noreferrer">https://github.com/yzhang-gh/vscode-markdown/issues/1010</a></p>
  <p><a href="https://github.com/yzhang-gh/vscode-markdown/issues/1008" rel="nofollow noreferrer">https://github.com/yzhang-gh/vscode-markdown/issues/1008</a></p>
  <p>So the built-in one can be disabled with:
  <code>&quot;markdown.math.enabled&quot;: false</code></p>
  <p>Or Markdown All in One's math renderer can be disabled with:
  <code>&quot;markdown.extension.math.enabled&quot;: false</code></p>