By Raj Jayavant · Updated
On desktop, click the gear icon in the player, choose Playback speed, and pick a value. The options run from 0.25x to 2x. On mobile, tap the screen, then the settings icon, then Playback speed.
There is also a keyboard shortcut: Shift , slows playback down and Shift . speeds it up, stepping through the same values.
No. YouTube corrects the pitch when the speed changes, so a video at 0.5x sounds slower but stays in the same key. This is what makes slow playback useful for music rather than a novelty. The detail is in does slowing down a video change the pitch.
The speed setting is global. If you want one difficult passage at half speed and the rest at normal, you are changing the setting back and forth manually every time you reach it.
The menu gives you a handful of preset values. If 0.5x is too slow and 0.75x is too fast for the passage you are working on, there is nothing in between.
For learning, what you usually want is a specific passage, slowed, on repeat. That is three things at once, and YouTube gives you a partial version of one of them.
PhraseLoop handles the combination: mark the start and end of the passage, set the speed anywhere between 0.25x and 2x, and it loops that section at that speed until you change it. Because the markers persist, you can raise the speed step by step as the passage gets easier without losing your place.
For working out notes by ear, half speed is usually the sweet spot: slow enough to separate a fast run into individual notes, fast enough that the phrase still hangs together musically.
For playing along, use the fastest speed at which you play accurately. That is often higher than you expect, and practicing below it wastes time. There is a fuller treatment in how to practice slowly and speed up.
Below about a quarter speed, audio quality degrades noticeably whatever tool you use. Pitch correction works by stretching the audio in time, and stretching it very far introduces artefacts.
If a passage is unusable even at 0.25x, the problem is usually that the section is too long rather than too fast. Shorten it to a couple of bars and it becomes tractable.