What debounce time should I set on my mouse?

Set 0 ms if your mouse has optical or magnetic switches, then set it down hard a few times to check for false clicks. With mechanical switches, start at the maker's own figure. For LAMZU and Fnatic that is 4 ms or higher. If the maker gives no figure, keep the factory default. Raise it 1 ms at a time, and only if you see double clicks. If you need more than 10 ms, Pulsar says the switch is defective.

What debounce time is

A mechanical mouse switch makes a click by pressing two metal contacts together. They do not meet cleanly. They touch, spring apart and touch again before they settle. That chatter is called bounce. Texas Instruments says many switches "can bounce for hundreds of microseconds after being pressed".

Debounce time is how long the mouse waits out that chatter. In Keychron's words, the firmware "ignores every further change on that button for a set number of milliseconds, then accepts the state it finds". Set it too short and the bounce gets read as a second click. That is a double click. A slam click has a different cause: the jolt of setting the mouse down hard fires a click you never pressed.

An optical switch reads the press with a beam of light, and a magnetic (Hall effect) switch reads it with a magnet and a sensor. Neither has metal contacts, so neither bounces. Razer says this removes "the need for debounce delay". Logitech calls its LIGHTFORCE switches hybrid optical-mechanical, and says that with optical actuation "debounce algorithms are no longer needed".

What each millisecond costs

Debounce is a wait, so it adds lag. Keychron says it delays every click "by up to that many milliseconds". TechPowerUp measured it: click latency "scales linearly" with the setting on the Pulsar X2N Crazylight, SCYROX V8, Akko Dash Ultra and Vaxee NP-01S V3. On the Glorious Model D3 Wireless and Rapoo VT2 Max it scales "largely linearly". The LAMZU Maya X is the one exception it found.

So the slider is close to a lag dial. Our click latency tests put most mice under 1 ms at their lowest setting. A 4 ms debounce can add up to four times that on top.

Worked through: a mechanical mouse at 4 ms

Take a mouse with mechanical switches and the LAMZU software. Fnatic's help page for that software says "a debounce of 4ms or higher is recommended" to avoid double clicks and slam clicks. So you start at 4 ms.

That can add up to 4 ms to each click. At 240 Hz one frame lasts 4.17 ms (derived), so 4 ms of debounce is close to a whole frame of your click-to-photon budget. Compare the Vaxee NP-01S V3, a mechanical mouse TechPowerUp measured at 0.54 ms wired with debounce at 0. TechPowerUp also reports no slam clicks on it "regardless of the set debounce time". If your mouse behaves like that, you can try lower than 4.

Now suppose that a year on, the left button starts to double click. Raise the setting to 5 ms and use the mouse for a day. Still doubling? Go to 6. Each step can cost up to one more millisecond of lag. If you reach 10 ms and it still doubles, stop. Pulsar's software guide says that "at over 10ms, the switches are considered defective". The fix then is a new switch, not a bigger number.

Debounce ranges and rules by brand

The Fnatic help page splits its 0 to 20 ms range by how much speed matters to you, not by switch: 0 ms for highly competitive play, 2 to 4 ms for casual games, 4 to 8 ms for relaxed ones. Read that with its own warning beside it. Low settings "may result in the occurrence of double clicks or slam clicking". Fnatic's BOLT does not go to 0 at all. Its OP software offers 1, 2, 4, 8 and 12 ms.

Zowie gives no millisecond values. Its FAQ has you power off, then hold the button while you switch on or plug in. TechPowerUp found the EC3-C ships on Normal. On Razer, a support moderator on Razer's own forum says the value "is set and saved onto the firmware" and cannot be changed in Synapse.

Why "5 to 10 ms, then test" is half right

Most guides say the default is 5 to 10 ms and you should experiment. Glorious says the same: "most gaming mice ship with a debounce default between 5 and 10 milliseconds". That is fine for a mechanical switch. It is wrong for an optical or magnetic one, where there is no bounce to wait out and every millisecond is lag for nothing. The advice persists because it was written when nearly every mouse used mechanical switches. Check which switch you have first. The switch guide explains the types.

Zero on an optical switch still needs one check. The Endgame Gear OP1we uses Kailh GO optical switches, and TechPowerUp found that "accidental clicks occur when slamming down the mouse if debounce time is set to 0/1 or 2 ms". Most mice it tested showed no such clicks, among them the Razer Viper V4 Pro, Pulsar X2N Crazylight and LAMZU Maya X. So after setting 0 ms, lift the mouse a few centimetres and drop it onto the pad a few times. If that fires a click, raise the setting 1 ms at a time until it stops.

Some mechanical mice have a third option. The Kailh GX switches in the Endgame Gear OP1 8K V2 have a top and a bottom contact. TechPowerUp notes this can provide "additional hardware debouncing, preventing unintended double-clicking". If your mouse has a mode like GX Safe Mode, it does the job the slider would.

Where this stops applying

The 0 ms rule covers the switches under the main buttons. Side buttons and the wheel may still be mechanical, which is why some software sets them apart. Hybrid switches with a mechanical mode, like Keychron's MagOptic, need checking in the mode you use. Ranges come from one software version each and can change with firmware. TechPowerUp's linear scaling is from one sample of each mouse. It shows the trend, not a figure your own mouse will match to the tenth. If your brand is not in the table, the rule still holds: switch type first, maker's figure second, 1 ms steps after that.

Frequently asked questions

What is a good debounce time for a gaming mouse?

0 ms on optical, magnetic or hybrid switches, because they do not bounce, as long as setting the mouse down hard does not fire a click. On mechanical switches, the maker's figure: Fnatic's help page for LAMZU software says 4 ms or higher avoids double clicks and slam clicks. Raise it 1 ms at a time if double clicks appear.

Is 0 ms debounce safe?

On optical and magnetic switches, usually. Razer says optical switches eliminate the need for debounce delay, and Logitech says debounce algorithms are no longer needed with its LIGHTFORCE optical actuation. On a mechanical switch it can cause double clicks. Slam clicks can happen even on optical switches: TechPowerUp saw them on the Endgame Gear OP1we, which uses Kailh GO optical switches, at 0, 1 and 2 ms. Set the mouse down hard a few times to check.

Does a higher debounce time add input lag?

Yes. Keychron says it delays every click by up to the full setting. TechPowerUp measured click latency rising linearly with the setting on four mice and largely linearly on two more. The LAMZU Maya X was the exception.

What debounce time means my switch is dying?

Pulsar's software guide says that at over 10 ms the switches are considered defective. Fnatic discourages 9 ms and up for games where speed matters. If you need that much to stop double clicks, replace the switch or the mouse.

Can I change debounce on a Razer or Logitech mouse?

Razer's optical mice: a Razer support moderator says it is set in firmware and cannot be changed in Synapse. Logitech publishes no debounce setting and says its LIGHTFORCE switches do not need one. Zowie C and CW mice have two click response settings, Fast and Normal, chosen by holding a button at power-on.