Something is wrong
Bluetooth headphones delayed
Bluetooth audio arrives late. That is not a fault; it is how the link survives dropouts, and every pair of wireless headphones does it. What varies is by how much, whether the video you are watching compensates, and whether anything can be done. Two measurements answer the first two, and the answer to the third is usually one of four things — three of them free.
The run, in order
Measure how far the sound is behind the picture, wearing the headphones
This is the number everything else is about. Watch the flash, move the click until they land together, and lock it in. Expect somewhere between 100 and 250 ms on ordinary Bluetooth; around 40 to 80 on a low-latency codec. Under about 45 ms you will not notice it and there is nothing to fix. Write the number down — it is what you will enter into a player later if it comes to that.
Measure the round trip with the headphones, then with a cable or the built-in speakers
This separates the Bluetooth link from everything else. The test sends a sweep out of the speakers and times its return through the microphone; on a headset it goes through the headset both ways. The difference between the two runs is what the link costs, exact even though each run has other things in it. If the wired figure is also high, the delay is in the computer and not the headphones, and the last step applies.
Check whether the video player is already compensating
Most phone players, streaming apps and modern desktop players delay the picture to match Bluetooth audio automatically — which is why films are usually fine and the delay only shows up in games, live video and calls. If a film in the usual app looks right and the sync test still measured 150 ms, the app is compensating and there is nothing to fix for films. The remaining steps are for the things that cannot compensate.
Check which codec and profile the link is using
Two things change the delay without touching the hardware. The codec: aptX Low Latency, aptX Adaptive and LC3 run at a fraction of the delay of SBC and AAC, but only when both the headphones and the computer support them — and many computers do not. The profile: the moment an application opens the microphone, the link drops to the headset profile, which has less delay and telephone-grade sound in both directions. If the delay changes when a call starts, that is why.
Enter the measured offset into the player that needs it
For players that do not compensate, the number from the first step is the fix. VLC: Tools, Track Synchronization, audio delay. Kodi and Plex: audio offset in playback settings. Most televisions: Sound, audio delay or lip sync. Enter the measured offset so the picture is held back to match. It is per player and per device, and it will be wrong if you switch back to wired, so remember where it is set.
For anything live, use a cable
Games, live streams, video calls and music you are playing along to cannot be compensated, because the picture cannot be delayed without the delay itself being the problem. For those there is no setting: a wired connection removes the delay rather than hiding it, and it is the only thing that does. Headphones with a detachable cable and a dongle-based wireless mode — the kind sold for gaming — exist precisely because of this.
If the sound is fine on cable but wrong on Bluetooth in some other way, check the channels
A different fault that arrives with the same headphones. The headset profile, when it is active, is mono and low quality; a pair that suddenly sounds thin and one-sided has switched profiles, not broken. The channel test shows whether stereo is arriving at all, which settles it.
Why the order matters
The first two steps are measurements, and they are done before anything is changed because they decide whether anything needs to be.
The sync test gives the number: how far behind the picture the sound arrives, on the headphones, as you actually hear it. Below about 45 ms there is no problem to solve, whatever the specification says. The latency test then splits that number: run it on the headphones and again on a cable, and the difference is what the Bluetooth link is adding, exactly. If the cable figure is also high, the headphones were never the cause.
Everything after that is about what can be done with the number. For anything that can be delayed — a film, a recorded video — the player either already compensates or can be told the number. For anything that cannot — a game, a call, a live stream — the number is the delay, and only a cable changes it.
Reading the outcome
Under 45 ms. In sync as far as anyone can tell. Nothing to fix.
Higher, and films look fine. The player is compensating, and the delay only exists where it cannot. Use a cable for those things and leave the rest alone.
Higher, and films look wrong in one player. That player is not compensating. Enter the measured number into its audio delay setting. VLC, Kodi, Plex and most televisions have one; browsers and most streaming apps handle it themselves.
Higher, on the cable too. The delay is in the computer — a driver, a virtual audio device, an effects layer — and the headphones are a bystander. The audio latency test page covers the settings that cause it.
Wrong in a different way — thin, mono, one-sided. The link has switched to the headset profile because something has the microphone open. Close it, or accept it for the length of the call.
The one that is not a fault at all
A Bluetooth delay of 150 ms on a film that looks perfectly in sync. The delay is real, the player has already hidden it, and there is nothing to do. Measuring it is worth doing once, so that the number is known when a game or a call makes it visible — and so that nobody buys new headphones to fix a film that was fine.
Common questions
Is there a setting that removes Bluetooth delay?
No. The delay is buffering, and the buffer is what stops the audio breaking up when the radio link stutters. Codecs designed for low latency shrink it — to around 40 to 80 ms — and that is as low as Bluetooth goes. Players can hide it by delaying the picture; nothing can remove it except a cable. Anyone selling a setting that eliminates it is describing compensation, which works for films and not for anything live.
Why do films look fine but games and calls do not?
Because a film can be delayed and a game cannot. The player knows the audio is going to Bluetooth, holds each frame back by the same amount, and the two arrive together. A game cannot hold back a frame that depends on what you just did, and a call cannot hold back the other person. Both show the delay raw, which is why the same headphones feel fine in one and wrong in the other.
What is a low-latency codec and do I have one?
A codec is how the audio is squeezed for the radio, and the common ones — SBC and AAC — buffer generously. aptX Low Latency, aptX Adaptive, Samsung Scalable and the newer LC3 buffer less. You have one only if both ends support the same one: the headphones and the transmitter. Phones vary; most Windows machines support SBC and AAC only unless a specific adapter is fitted; Macs support AAC. The headphone box says what the headphones support; the sync test says what you are actually getting.
The delay changes when I join a call. Why?
The link switched profiles. Bluetooth carries high-quality one-way audio on one profile and two-way telephone-grade audio on another, and it changes to the second the moment an application opens the microphone. The second has less delay and much worse sound. That is why music sounds good on the same headphones that make you sound like a phone from 1995, and why the delay is different in the two cases.
My AirPods are fine on my iPhone and late on my PC.
Both readings are right. AirPods negotiate a lower-delay mode with Apple devices than with anything else, and on a Windows machine they fall back to the ordinary codec with the ordinary buffer. Nothing is broken; the two links are genuinely different. Measure each with the sync test and you will see two different numbers from the same headphones.
Should I just buy different headphones?
Only if you need low delay and cannot use a cable. For films, the ones you have are fine — the player compensates. For games and live video, headphones with a dedicated dongle — the wireless mode sold for gaming — run at delays close to wired, because they use their own radio rather than Bluetooth. That is a real difference and worth paying for if the use case is real; it is not worth it to fix a film that was already fine.