Add playback speed controls to web players with keyboard shortcuts
A userscript that adds playback-speed controls and a perceptually-correct volume curve to web video players. It supports Plex and YouTube out of the box, and an opt-in perceptual volume curve for any other site with an HTML5 <video>.
| Feature | Plex | YouTube | Any other site |
|---|---|---|---|
| Playback speed — keyboard | ✅ | ✅ | — |
| Playback speed — on-screen buttons | ✅ | — | — |
| Natural Volume Control | ✅ (on by default) | ✅ (on by default) | ✅ (opt-in per origin) |
| Skip Auto-Play countdown | ✅ (on by default) | — | — |
Per-feature toggles for the current site are available from the Tampermonkey menu when installed as a userscript.
There are multiple ways to alter the playback speed:
Cycle keys — < or , slow down by one step; > or . speed up by one step. The cycle list is:
Quick-set keys — number keys 1–9 jump directly to a preset speed:
number key |
mapped to speed |
|---|---|
| 1 | 1 |
| 2 | 1.5 |
| 3 | 2 |
| 4 | 3 |
| 5 | 4 |
| 6 | 5 |
| 7 | 7 |
| 8 | 8 |
| 9 | 10 |
Keyboard shortcuts are ignored while typing in input fields, textareas, or contenteditable elements.
Web players (Plex, YouTube, and most sites) wire their volume slider linearly to HTMLMediaElement.volume. Human hearing is logarithmic, so a linear slider feels overwhelmingly loud at the top and nearly silent for most of its travel. This script replaces the curve with a dB-linear mapping so equal slider movements produce equal-sounding loudness changes — the same fix Discord applies to its own volume sliders.
Design notes and references: designs/natural-volume-control.md.
When installed as a userscript, the Tampermonkey menu shows toggles relevant to the current site. Changing a toggle prompts to reload the page so the change takes effect. Settings persist across sessions.
This script predates Plex's own playback-speed support, announced on May 15 2024, and still offers a few things Plex's native controls don't.
| This Script | Native Plex | |
|---|---|---|
| More speed options to choose from | ✅ (cycle through with ,.<> keys: 0.5, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.5, 3, 3, 5, 4, 5, 6, 7, 8, 9, 10, 15, 20 hot key with number keys: 1, 1.5, 2, 3, 4, 5, 7, 8, 10) |
❌ (0.5x, 0.75x, Normal, 1.25x, 1.5x, 1.75x, and 2x) |
| Keyboard shortcuts | ✅ (cycle through with ,.<> keys or hot key with number keys, on top of mouse clicking buttons) |
❌ (mouse clicking only) |
| Does not require plex-pass | ✅ | ❌ |
| Support browser clients (incl. iOS devices) | ✅ | ✅ |
| Support non-browser clients | ❌ | ✅ |
| Perceptual (dB-linear) volume slider | ✅ | ❌ |
| Auto-skip "Play Next" countdown | ✅ | ❌ |
When Plex shows the auto-play countdown at the end of an episode, the script auto-clicks "Play Next" if Plex's own auto-play checkbox is on. Toggle from the Tampermonkey menu: "Skip Auto Play Countdown: Enabled / Disabled".
YouTube applies per-video loudness normalization that caps video.volume below 1.0 for loud content. The Natural Volume curve detects this cap (via loudnessDb from YouTube's player API) and anchors its endpoints to the cap, so the slider still reaches "as loud as YouTube will allow" without double-attenuating.
Playback speed on YouTube uses the same keyboard bindings as Plex; on-screen buttons are not injected on YouTube to avoid clashing with YouTube's own speed UI.
Natural Volume Control can be enabled on any other site from the Tampermonkey menu — look for Natural Volume (<origin>). The setting is stored per-origin, so enabling it on one site does not affect another. A warning is shown the first time you enable it on a site that hasn't been tested; if you hit any audio issues, disable it from the same menu.
Playback-speed shortcuts are not active on generic sites.
The script runs in two modes:
index.html) — Plex features only, with defaults hardcoded (no settings UI). If a userscript instance is running on the same page, the static instance steps aside automatically.This is the best option if you load the Plex web client off your Plex server from many different devices & browser profiles. It runs the script in static-script mode — Plex features only, no settings UI. Use a userscript install alongside it if you also want YouTube support or per-feature toggles.
The following steps assume the Plex server is deployed with the linuxserver/plex docker image. Installation for other deployment options should be similar.
Install and update may be automated as follows:
# inject_PlaybackSpeedControl.sh
cd /usr/lib/plexmediaserver/Resources/Plug-ins-*/WebClient.bundle/Contents/Resources
wget -O "js/PlaybackSpeedControl.js" "https://raw.githubusercontent.com/ZigZagT/Web-Player-Playback-Speed-Control/master/PlaybackSpeedControl.user.js"
sed -i 's#</head>#<script src="/web/js/PlaybackSpeedControl.js"></script></head>#' index.html
inject_PlaybackSpeedControl.sh.chmod a+x inject_PlaybackSpeedControl.sh
inject_PlaybackSpeedControl.sh script into container as start up script:# docker-compose.yaml
services:
plex:
image: linuxserver/plex
tmpfs:
- /tmp
volumes:
# ... other volumes ...
- /path/to/inject_PlaybackSpeedControl.sh:/etc/cont-init.d/99-inject_PlaybackSpeedControl.sh
devices:
- /dev/dri:/dev/dri
restart: always
This method keeps the scripts up-to-date whenever the plex server restarts.
The automated script mentioned above essentially performs the following tasks:
linuxserver/plex:1.40.0 the WebClient bundle is located at /usr/lib/plexmediaserver/Resources/Plug-ins-c29d4c0c8/WebClient.bundle/Contents/Resources.PlaybackSpeedControl.user.js file into the js folder..user part from the file extension. Otherwise some browser user script extensions may mistakenly hijack the script request.index.html file, add a script tag that points to the script file. The path shuold be prefixed with /web. For example, if script file is stored at js/PlaybackSpeedControl.js, the <script> tag should be <script src="/web/js/PlaybackSpeedControl.js"></script>
The script will not update automatically with this installation.
Works for all supported sites (Plex, YouTube, and any site you opt in to Natural Volume on).
Works for all supported sites.
Save Location setting configured.Save Location of your choice.