GCD / Spell Queue Profiler

Every millisecond between two GCDs is damage or healing you never get back. GCD / Spell Queue Profiler measures the idle time between each of your global cooldowns and tells you, cast by cast, whether the next spell was already queued when the previous GCD or cast ended.

When you press your next ability inside the Spell Queue Window (the last 400 ms of a GCD or cast by default), the game fires it the instant the current one finishes, so the gap is about 0 ms. Press it after the GCD has already ended and you leave a gap: your reaction time plus your latency. Those small gaps add up quickly. 40 ms lost on each of 300 GCDs is 12 seconds of doing nothing in a single boss fight.

GCD / Spell Queue Profiler makes those gaps visible.

Features

Gap after every GCD: idle time between the end of one GCD (or hard cast or channel) and the start of the next, shown live. Queued %: the share of your GCDs that fired off the spell queue (gap of 50 ms or less by default). Full statistics: average, median, 90th percentile and worst gap, plus total time lost between casts and how many GCDs that adds up to. Live gap chart: your last 40 GCDs as colour-coded bars: 🟩 queued 🟨 late 🟥 missed ⬜ downtime

Hover a bar to see the spell, the gap and the fight time.

Downtime filtering: long pauses (movement, mechanics, intermissions; over 2 s by default) are counted separately and kept out of your averages.

• Casts, channels and empowers: a hard cast longer than the GCD counts as busy until it ends, and clipping a channel with your next spell counts as no gap.
• End-of-combat summary in chat, with a tip if your queue usage is low.
• Fight history: summaries of your last 25 fights are saved, so you can compare pulls and see yourself improve.
• Minimap button and Addon Compartment entry to show or hide the window.
• Lightweight: one cheap check per frame, and only while you are recording.

How it helps you

• Find damage and healing you didn't know you were losing. Most players have no idea how much time slips away between casts. GCD / Spell Queue Profiler shows exactly how much, often several seconds per fight, without anything else in your rotation changing.
• Build the spell-queue habit. Live feedback after every cast trains you to press your next spell a little early, until queuing becomes muscle memory.
• Feedback while you play, not after. You see every gap the moment it happens, instead of digging through logs after the raid.
• Spot your weak points. Hover any bar to see which spell came after a gap, so you can find the parts of your rotation where you hesitate.
• Track your progress. Saved fight history lets you compare pulls and nights and watch your queued % climb.
• Separate mistakes from mechanics. Long pauses for movement or boss mechanics are set aside, so your numbers reflect how you play, not the encounter.
• Works for every class and role. Tanks, healers and DPS all benefit from a smoother, gap-free flow of casts.
• Works everywhere you play: target dummies, the open world, Mythic+ and raids.

How to use

1. Install it and enter combat. Recording starts and stops on its own with combat.
2. Watch the window, or read the summary in chat after the pull.
3. Aim for a Queued % in the 90s. If it's low, press your next spell earlier, during the last part of the current GCD or cast, and let the queue fire it for you.

Target dummies are a good place to practise before taking the habit into dungeons and raids.

Slash commands

Minimap button: left-click shows or hides the window, right-click prints the report, and you can drag it around the minimap edge.

Good to know

• A gap isn't always a mistake. Waiting for energy or another resource, moving out of a mechanic, or a target out of range all show up as gaps too. The tool shows where time went; you decide why.
• In restricted combat, the GCD count is an estimate. When one GCD flows straight into the next without the GCD ever dropping, the profiler uses timing to tell a queued GCD apart from an off-GCD spell woven in. The gap values themselves don't depend on that estimate.
• The Spell Queue Window is a game setting (the SpellQueueWindow CVar). GCD / Spell Queue Profiler shows your current value in its footer but never changes it.