SOCD & Snap Tap Test

SOCD stands for Simultaneous Opposing Cardinal Directions — pressing two opposite movement keys at once, like A and D for strafing left and right, or W and S for forward and back. Human players do it constantly; the question is what the keyboard does about it.

Many keyboards and controllers apply a deliberate rule to that overlap window instead of sending both signals. That rule is the SOCD resolution mode. It decides which direction — if any — actually reaches the game when both keys are down.

The rules live in the keyboard's firmware and run every scan cycle, before the operating system ever hears about your keys. A mode like last-input priority (marketed as Snap Tap, CSOCD, or dual-input by various vendors) means the newest key instantly steals the slot — and, in some implementations, presses the old key back the moment the new one is let go.

Every mode is defined by one decision: which signal survives the overlap, and what happens when a key in the pair is released.

The guided trial asks you to do three things in order — hold one key, add its opposite, then lift the first — and records the exact event sequence the browser reports, with millisecond timing from performance.now(). The pattern of those events is the evidence:

• Auto-release signature. A release event for the held key lands ≤ 25 ms after the opposite press — far too fast for a reaction. Consistent auto-releases are browser-visible evidence of last-input-style behavior.
• Re-actuation. The first key goes active again right after the opposite key is released, while nobody pressed it. This is what a Snap Tap board "re-presses" for its owner.
• Suppression hand-off. The opposite key never arrives during the overlap, then appears the instant (first-input) or well after (neutral) the first key is lifted.
• Sustained overlap. Both keys stay down together for the whole window — the browser sees raw passthrough, no filtering.

Each trial is classified on its own; a verdict only appears when at least two valid trials agree, and never flags a single suspicious event. Trials that lose window focus are discarded, not analyzed — half-typed evidence is worse than none.

Counter-Strike's fastest movement trick is the counter-strafe: tap one direction, then the other, to stop instantly and fire accurately. Doing it by hand takes real timing and practice — and a keyboard with Snap Tap-style resolution performs the swap automatically the instant you touch the opposite key.

So in late 2024 Valve shipped its own SOCD filter: if both A and D are registered as held, the game sums the inputs to zero. A hardware Snap Tap stops working the moment the game applies neutral-style resolution on top of it — and CS2 added a rule that explicitly bans configurations that exploit the overlap, with players reporting that Valve has, on detection, applied cooldowns and competitive bans to accounts using them.

That's the practical use for this test: figure out which behavior your keyboard shows in the browser, so you know what CS2's filter is sitting on top of.

SOCD didn't start in shooters. Hitbox and all-button fight sticks made SOCD handling a core spec: pressing left and right together on a chorded pad produces a direction, not a cancellation. Competitive fighting-game rules — Sonic, Capcom's V.S. System events, and the major circuits — settled on neutral: opposing directions cancel to nothing, and no auto-re-press afterimages are allowed.

The same physical action reads completely differently in each scene. A Snap Tap keyboard is an unfair advantage in CS2 and mostly a non-issue on a pad with neutral SOCD built in. When a tool "detects SOCD," know which of those definitions you're testing against — this page covers the FPS definition, where last-input priority and re-actuation are the telltale signs.

A web page only ever receives keyboard events after the entire input chain has finished its work: the firmware scan, the OS keyboard driver, and the browser's event dispatch each sit in front of the JavaScript that draws this page.

That is why every verdict on this page is confidence-based. The report describes what the events were consistent with, never what the hardware is. Treat a firm reading as a strong hint worth confirming with your keyboard's driver software — never as a substitute for it.

Do I need a special keyboard to run this test?
No. Press your opposing key pair on any keyboard and the analyzer reports exactly what the browser received, including the case where nothing was filtered at all.

Does a clean result prove my keyboard has no SOCD handling?
It proves nothing was applied to the events this page saw. Firmware can treat raw game input differently, so confirm a surprising result in your keyboard software.

Which keys should I test?
The pair you actually play with. A and D covers most first-person shooters; left and right arrows cover most fighting-game pads and stick layouts.

Is SOCD cleaning cheating?
That depends entirely on the game. Counter-Strike 2 disallows it, while many fighting games expect a defined resolution behaviour. Check the rules of the title you play.

Can I test a controller or gamepad here?
No. This analyzer reads keyboard events only, so a controller sends nothing it can measure.