1.6.4 Download ((better)) — Optifine

Do not download OptiFine from third-party mirror sites, such as 9Minecraft, MinecraftSix, or random MediaFire links. These often contain adware, spyware, or outdated versions.

You need Java installed. Download Java 8 from Adoptium or Oracle. After installation, right-click the .jar → Open with → Java. optifine 1.6.4 download

If the main link fails, use a Mirror Link directly. Do not download OptiFine from third-party mirror sites,