Iris Shaders

Iris Shaders: Bringing Shader Packs Back

Iris is a modern shader pack loader built to stay compatible with existing OptiFine shader packs, and with more than 140 million downloads it's the go-to way to get dynamic shadows, reflections, and improved lighting into Minecraft. Like any shader mod, Iris is client-only — it renders what a player sees locally and has no role whatsoever on a server.

That means you should never add Iris to your server's mods folder; it belongs in your players' client installation, typically paired with Sodium, whose rendering engine Iris depends on.

For modpack authors: If you're offering customers a visually enhanced modpack, just document Iris and a compatible shader pack in the client setup guide — the server itself starts and runs completely independent of it.

Plan the rollout and operation

Test Iris together with Sodium and exactly one shader pack. Publish a working baseline combination but do not require shaders because GPU capability and drivers vary widely. Check joining, dimension changes, water, weather, and brightly lit bases. For rendering problems, the player should start first without the shader pack and then without Iris; the server remains unchanged throughout that diagnosis.

For a clean rollout, create a separate client profile and record the Minecraft, loader, and mod versions. Start without other optional mods, join the server, and check menus, the resource pack, dimension travel, and the actual feature. Add rendering, interface, and convenience mods back one at a time afterward. Publish the tested combination as a recommendation, not a server promise, because hardware and local settings differ. After an update, compare logs and behaviour with a fresh profile before reusing old configuration files. Keep the mod out of the server directory while its project page explicitly classifies it as client-side. On failure, the world remains untouched: the affected player disables the local file or returns to the documented version. For support, request a screenshot of the active profile instance, latest.log, and a list of other graphics mods; these show whether the loader, driver, or an overlap is responsible instead of the server.