Data encoding

Using Object Cache Pro’s serializer and compression configuration options reduces Redis memory usage by 70-80% and greatly reduces network communication.

While that’s fantastic, setting up, enabling and changing serialization and compression requires some extra steps.


To use the igbinary serializer, PHP must run the igbinary PHP extension and PhpRedis must be compiled with the --enable-redis-igbinary flag.

Using any of the compressions requires PhpRedis to be compiled with their correlated flags, such as --enable-redis-zstd and --enable-redis-lz4.

Changing serializer/compression

Every time the serializer or compression configuration option is changed, you must flush your entire Redis database to avoid corrupt data and crashing your site.

If you can afford downtime in your development or staging environment, just go ahead and change serializer / compression option and run redis-cli flushdb.

In production environments that cannot afford downtime it’s recommended to:

  1. Disable the object cache: wp redis disable
  2. Run wp redis cli and then flushdb
  3. Change serializer / compression option
  4. Re-enable the object cache: wp redis enable

Choosing a compression algorithm

The zstd algorithm compresses data the smallest, lz4 compresses data the fastest and lzf should only be used when the others aren’t available.