How to Install Shaders in Minecraft (Java)

Guide Java Bedrock

Quick answer: Install Iris (recommended) or OptiFine - both free - then drop a shader pack ZIP into the shaderpacks folder and enable it in Video Settings > Shaders. Shaders are Java Edition only; Bedrock has its own Vibrant Visuals setting.

What you need

Minecraft Java Edition
Iris (with Fabric) or OptiFine - both free downloads
A shader pack ZIP (BSL, Complementary, Sildur's...)
A PC with a decent GPU - shaders are heavy

Step by step

Choose your loader: Iris + Sodium is the modern pick (better performance and mod compatibility); OptiFine is the classic all-in-one. Both are free - never pay for shaders or installers.
For Iris: run the Fabric installer for your Minecraft version, then drop the Iris and Sodium JARs into the mods folder. For OptiFine: download the JAR matching your game version and run it - it creates a launcher profile.
Launch the game once with that profile, then close it. A shaderpacks folder appears inside your .minecraft directory.
Download a shader pack (it comes as a ZIP - do not unzip it) and move the ZIP into the shaderpacks folder.
In-game: Options > Video Settings > Shaders, select the pack, click Done. The world relights itself with the new look.
Tune performance: shader packs have Low/Medium/High presets. If your FPS drops hard, lower the preset before blaming your PC.
Bedrock players: shaders as such do not exist - the built-in Vibrant Visuals graphics setting (on supported devices) is the official equivalent.

Java vs Bedrock

Java Edition only. Bedrock (Windows, console, mobile) cannot install shader packs - use Vibrant Visuals or marketplace looks instead.

Versions: Shader support via OptiFine/Iris works on all current Java versions. Iris updates faster on new releases; OptiFine sometimes lags behind version updates.

Frequently asked questions

Are shaders free?

Yes. Iris, OptiFine and every major shader pack (BSL, Complementary, Sildur's) are free. Sites charging for shader downloads or 'premium installers' are scams - get everything from the official pages.

Shaders vs texture packs - what is the difference?

Texture packs change how blocks look; shaders change the lighting, shadows, water and sky. They stack: most people run both together.

My game crashes with shaders - what now?

Update your graphics drivers first. Then try Iris instead of OptiFine (or vice versa), pick the Low preset, and check the pack matches your Minecraft version. Old packs on new versions are the most common crash cause.