Troubleshooting slow builds

This page contains a list of the most common issues that are slowing down builds.

In case you are waiting a long time for your builds to finish or your builds are terminated by exceeding general resource limits, this troubleshooting guide will help you resolve some of the most common issues causing slow builds. Even if you are not facing any immediate performance issues, it’s always good to be familiar with the most common ones.

Build resources on Read the Docs are limited to make sure that users don’t overwhelm our build systems. The current build limits can be found on our Build resources reference.


Please help us keep this section updated and contribute your own error resolutions, performance improvements, etc. Send in your helpful comments or ideas 💡 to or contribute directly by clicking Edit on GitHub in the top right corner of this page.

Reduce formats you’re building

You can change the formats of docs that you’re building with our Configuration file overview, see formats.

In particular, the htmlzip takes up a decent amount of memory and time, so disabling that format might solve your problem.

Reduce documentation build dependencies

A lot of projects reuse their requirements file for their documentation builds. If there are extra packages that you don’t need for building docs, you can create a custom requirements file just for documentation. This should speed up your documentation builds, as well as reduce your memory footprint.

Use mamba instead of conda

If you need conda packages to build your documentation, you can use mamba as a drop-in replacement to conda, which requires less memory and is noticeably faster.

Document Python modules API statically

If you are installing a lot of Python dependencies just to document your Python modules API using sphinx.ext.autodoc, you can give a try to sphinx-autoapi Sphinx’s extension instead which should produce the exact same output but running statically. This could drastically reduce the memory and bandwidth required to build your docs.

Requests more resources

If you still have problems building your documentation, we can increase build limits on a per-project basis, sending an email to providing a good reason why your documentation needs more resources.