Jamming to Your Own Beat: How to Play Custom Songs in Project SEKAI

If you have spent any amount of time scrolling through TikTok, YouTube, or X (formerly Twitter), you have probably stumbled upon jaw-dropping rhythm game clips of Project SEKAI: Colorful Stage! featuring chaotic, lightning-fast charts, internet memes, or underground Vocaloid tracks that are nowhere to be found in the official game.

Naturally, this leads to the ultimate question for any rhythm game enthusiast: How do I get custom songs into Project SEKAI?

The short answer? You can’t directly mod or inject custom music files into the official app. Doing so violates the game’s terms of service, risks your account getting banned, and usually results in broken application code.

However, the rhythm gaming community has a brilliant workaround. Instead of messing with the official game files, players use a dedicated companion platform called Sonolus to play fan-made charts with the exact UI, look, and feel of Project SEKAI.

Here is your complete, step-by-step guide to diving into the world of custom Project SEKAI charts safely and easily.

Step 1: Understand the Ecosystem (Meet Sonolus)

Because the official global and Japanese servers of Project SEKAI do not feature a built-in custom song workshop, the community relies heavily on Sonolus.