osu! preview

osu! preview is a browser extension that allows you to preview osu!standard beatmaps in your browser. It correctly plays most maps, renders 99% similarly to the osu! client, gives you a seekbar to jump to any part of the map, allows you to adjust all volumes and background dim, it has support for mods (EZ, HR, HT, DT, HD, FL), skins, and autoplay.

Repository link: https://github.com/TechnoZamb/osu-preview

Controls:
Spacebar - Play/pause
Mouse wheel - Volume (hover over each channel to change its volume individually)
Left/Right arrows - Rewind/skip 3 seconds
Number/Numpad 0-9 - Jump to 0-90% of the beatmap
Tab - Open/close 'More' panel

Buttons used to activate/deactivate mods in osu! also work in osu! preview:
Q - EZ, E - HT, A - HR, D - DT, F - HD, G - FL