python · AA-Turner · Apr 25, 2025 · Apr 25, 2025
diff --git a/Doc/library/gzip.rst b/Doc/library/gzip.rst
@@ -253,6 +253,10 @@ Example of how to GZIP compress a binary string::
      The basic data compression module needed to support the :program:`gzip` file
      format.

+   In case gzip (de)compression is a bottleneck, the `python-isal`_
+   package speeds up (de)compression with a mostly compatible API.
+
+   .. _python-isal: https://github.com/pycompression/python-isal

 .. program:: gzip


diff --git a/Doc/library/zlib.rst b/Doc/library/zlib.rst
@@ -341,3 +341,8 @@ the following constants:
   http://www.zlib.net/manual.html
      The zlib manual explains  the semantics and usage of the library's many
      functions.
+
+   In case gzip (de)compression is a bottleneck, the `python-isal`_
+   package speeds up (de)compression with a mostly compatible API.
+
+   .. _python-isal: https://github.com/pycompression/python-isal