php.ini settings

Settings are edited per PHP version, not per site, because one php-fpm pool serves every site on that version.

rex php settings 8.3
rex php settings 8.3 set memory_limit=512M
rex php settings 8.3 set upload_max_filesize=64M

The app has the same editor on each version’s card in Settings.

Changing one restarts the pool

A set restarts that version’s php-fpm pool so the change takes effect — and every site on that version briefly restarts with it. Expected, quick, and worth knowing before you do it with a long request in flight.

The list is a whitelist

Not every ini directive is exposed

The editable set covers the directives local development actually needs — memory limits, upload and post sizes, execution time, error reporting, the OPcache knobs.

Directives that would break the pool, contradict how rexenv wires php-fpm, or silently disable something the app depends on are not offered. A setting that can only produce a broken pool is not a choice.

The usual ones

Setting	Why you would raise it
memory_limit	Large imports, page builders, WooCommerce with many extensions
upload_max_filesize	Media uploads failing at the WordPress level
post_max_size	Must be ≥ upload_max_filesize, or uploads fail confusingly
max_execution_time	Long imports and migrations
display_errors	Seeing the error instead of a white page

`post_max_size` is the one people miss

Raising upload_max_filesize alone does nothing if post_max_size is lower — the upload fails with an unhelpful message, because PHP discards the whole request body before WordPress sees it. Raise both.

Per-site alternatives

For something genuinely per site rather than per version:

• Per-site environment variables, in the site’s settings or rex site env.
• .htaccess with php_value directives, if the site uses the Apache override — nginx cannot read those.
• ini_set() in the application, for anything settable at runtime.

Checking what is live

The site’s Terminal tab:

php -i | grep memory_limit

That reads the CLI’s ini rather than the pool’s, so for the value the web request actually sees, use a phpinfo() page or check the site’s Environment card in the app.