KEY HIGHLIGHTS

01 TIMING

0.001-Second Precision Timing

Zero-Lag Audio & Input Sync

Reduced audio and input delay down to 0.001 seconds so every tap registers exactly when you hit it.

Strict arcade-grade timing windows: KOOL (±18ms), COOL (±40ms), GOOD (±75ms)
Smooth, glitch-free audio playback with zero stutter even during intense songs
Full support for 60Hz displays up to 144Hz, 240Hz, and 360Hz+ gaming monitors

02 NO INSTALL

Zero Downloads, Instant Play

Click and Play on Any Machine

No massive downloads or complex setups. Click a link and start playing immediately in your browser.

0 MB install footprint: loads in seconds straight from your web browser
High scores, favorite songs, and key bindings saved automatically in your browser
Full mechanical keyboard rollover support so rapid bursts and chords never drop

03 MULTIPLAYER

Real-Time Multiplayer Duels

Note-by-Note Live Battles

Not just comparing final scores. Duel head-to-head live to the exact same music in real time.

Live score leads and combo streaks updated note-by-note on screen
100% fair and synchronized note charts for every player in the room
Automated match verification to keep the competitive ranked ladder fair

04 BEATMAPS

Play Your osu!mania Library

Drag & Drop Import and Chart Editor

Import your existing osu!mania collection right into the browser, or create custom charts on the fly.

Full support for 4K, 5K, 6K, and 7K key configurations
Simply drag and drop .osz files directly into the window to play and save
Built-in browser chart editor to arrange notes with live audio and instant test play

PLATFORM COMPARISON

FEATURE	RHYTHMIO	LEGACY WEB GAMES	DESKTOP PC CLIENTS
Installation & Setup	0 MB (Play instantly from URL)	0 MB (Laggy flash / old web games)	10 GB ~ 60 GB + driver setup
Audio Sync & Latency	Instant sync, no delay (<12ms)	Noticeable audio lag (50~150ms)	Requires audio driver tuning (<10ms)
Input Accuracy	0.001s instant key response	Input lag tied to frame rate	Native client thread (<1ms)
High Refresh Rate Displays	Uncapped (60Hz ~ 360Hz+)	Locked to 60Hz	Uncapped
Multiplayer Experience	Live note-by-note duels	Async score submission only	Real-time multiplayer
Beatmap Compatibility	Drag-and-drop osu!mania import	Locked to proprietary songs	Requires converters or plugins

THE STORY

Rhythmio is a browser-based 4K rhythm game built for anyone who loves fast-paced music games. Jump in instantly without downloading massive game files, enjoy 0.001-second precision timing, and duel other players in real time.

Why a browser game?

Traditional rhythm games often require massive multi-gigabyte downloads, intrusive software, and tedious audio driver tweaking before you can even hit your first note. Older web games, on the other hand, suffered from sluggish timing and missed keypresses.

We built Rhythmio to break those limits—delivering the crisp, arcade-grade feedback and responsive hand feel of a dedicated client straight through a single web link.

4 Key Highlights

1. 0.001-Second Precision

Your keypresses are measured with sub-millisecond accuracy down to 0.001 seconds, completely decoupled from visual frame rates. What you hit is what you get: honest, satisfying, and arcade-tight.

Strict arcade timing windows ensure your skill determines your rank.
Clean, glitch-free audio playback even on modest hardware.
Full support for 60Hz displays up to 144Hz, 240Hz, and 360Hz+ high refresh rate gaming monitors.

2. 0 MB Download, Instant URL Launch

No installers, no administrator privileges, and no OS restrictions. Open the link on Windows, Mac, Linux, or a Chromebook, plug in your keyboard, and play right away.

Zero disk space wasted on lengthy installations.
High scores, favorites, and custom key bindings are saved automatically in your browser.
Full support for rapid key spamming and complex multi-key chords without ghosting.

3. Real-Time Multiplayer Arena

Not just comparing score totals after the song finishes. Players duel in real time to the exact same music and identical note sequences.

Watch live score leads and combo streaks shift with every single note you hit.
100% fair and synchronized conditions for pure skill-based duels.
Automated match verification to keep the ranked ladder fair and trustworthy.

4. Play Your osu!mania Library

Bring your favorite charts with you.

Seamless support for 4K, 5K, 6K, and 7K key modes.
Simply drag and drop .osz beatmap files directly into your browser window to start playing.
Built-in chart editor to inspect waveforms, place notes, and test play instantly.

ABOUT RHYTHMIO

FASTER, LIGHTER, MORE ACCURATE