The queue that read forty this morning now says six hundred, and you are sure you changed nothing. You probably did change something, and the good news is that the fix almost never involves the reset button you are tempted to hit.

An overnight spike in your review queue is alarming, and the instinct is to make it go away fast. Resist that instinct, because the fastest-looking fixes are the ones that erase your progress. When your spaced repetition due count explodes, it is usually a setting or algorithm change rather than a week of missed studying, and once you know which cause you are dealing with, you can spread the load back out without touching the memory data you have spent months building.

A sudden spike in due cards is most often caused by a setting change, especially turning on the FSRS scheduler or re-optimizing it with “reschedule cards on change” enabled, raising your desired retention, or importing a big deck. The mistake that makes it worse is resetting or “forgetting” cards, which wipes your interval history and restarts learning. Instead, diagnose what changed, cap your reviews per day, pause new cards, and use postpone or load-balancing tools to smear the backlog across the coming days. Modern scheduling handles overdue cards gracefully, so a steady daily target clears the pile in a week or two without losing a thing.

Start by figuring out what changed, because the cause points to the cure. A missed week is the obvious suspect, but an overnight jump is more often one of these.

• You turned on FSRS, or re-optimized it, with “reschedule cards on change” checked. The Anki manual is explicit that this option is not recommended and “will often result in a large number of cards becoming due.” This is the most common culprit.
• You raised your desired retention. Even a few points higher means shorter intervals and more cards every day.
• You imported a large shared deck, or unsuspended a big batch of cards, flooding the new-card queue.
• You bumped new cards per day or removed a review cap, or changed a maximum interval.
• Your day rollover shifted, so a change to “next day starts at” pulled a day’s cards forward.
• You came back from a break. The expected cause, though usually not the overnight one.

Check your deck options history before you do anything else. If you can name the change, you can often reverse it directly, and the panic drains out of the number pretty quickly.

Here is the trap. When the count looks impossible, “reset” and “forget” feel like relief, and they are the one thing you should not do. Using Forget or resetting a card wipes its stability and interval history and restarts it as if you had never seen it, which throws away exactly the progress you were trying to protect.

A blanket “reschedule all cards” is gentler but still a problem, because it re-bunches your reviews into a fresh clump. FSRS rescheduling uses your memory data rather than erasing it, so it is not a true reset, but applied to your whole collection at once it can recreate the very spike you are trying to solve. The goal is to spread the existing cards out, not to rebuild their history from scratch.

Once you know the cause, the recovery is calm and mechanical. Work through it in order.

• Diagnose first. Confirm the cause in your deck options before changing anything, so you do not stack a second mistake on the first.
• Cap your reviews per day. Set a comfortable maximum per deck so the queue is a finite number you can finish, not an open-ended eight hundred.
• Pause new cards. Set new cards per day to zero until the backlog clears, so you are not adding to the pile while you dig out.
• Spread, do not reset. Use the FSRS Helper add-on’s Postpone and Load Balance features to smear the overdue cards across the coming days, and turn on Easy Days for the days you know you will be busy.
• Do the smartest cards first. Sort your due cards by retrievability and clear the ones you still know cold, which shrinks the queue fast without stress.
• Set a daily target and hold it. Pick a sustainable number, do it every day, and let the pile shrink on a schedule instead of in one brutal session.

If the spike really was a missed stretch rather than a setting, our guide to rebuilding your schedule after a missed week is the better starting point, and our catch-up calculator helps you set a realistic daily target.

A one-tab spreadsheet turns the panic into a countdown you can watch shrink. Make one row per deck plus a total row, with these columns:

• Deck name.
• Total due today, the current backlog for that deck.
• Daily target, the review cap you can actually sustain.
• New cards per day, set to zero until you recover.
• Days to clear, which is total due divided by your daily target.
• Running remaining, updated each day so you can see the finish line.

Seeing “eleven days to clear” instead of “six hundred due” is a surprisingly large psychological difference, and it keeps you from over-correcting halfway through.

One reassuring fact makes all of this easier. Modern scheduling, FSRS, does not punish you for late reviews the way the old algorithm did. A card that comes due a few days late does not blow up your future intervals, and honest answers keep your parameters accurate even after a gap. FSRS is the default scheduler for fresh Anki installs now, though existing profiles stay on the older system until you switch.

So trust the recovery. Clear a steady number each day, re-optimize your parameters after a week or two once the dust settles, and the queue will normalize on its own. You do not need to force it back into shape, and forcing it is usually what caused the explosion in the first place.

Most often because of a setting change rather than missed days. Turning on FSRS or re-optimizing it with “reschedule cards on change” enabled, raising your desired retention, importing a large deck, or unsuspending a batch of cards can all flood the queue overnight. Check your deck options history to identify which one it was.

Usually not as a blanket action. Rescheduling your whole collection at once tends to re-bunch reviews into a new clump. It is better to leave the intervals alone and spread the existing due cards out using postpone or load-balancing tools, while capping your daily reviews and pausing new cards.

Not if you avoid the reset and forget functions, which wipe a card’s history and restart learning. Working through the backlog normally, even late, preserves your progress. FSRS handles overdue cards gracefully, so answering them honestly keeps your scheduling accurate.

Use the FSRS Helper add-on’s Postpone and Load Balance features to distribute overdue cards across upcoming days, and set a maximum reviews per day so the queue stays finite. Enable Easy Days for days you know will be busy so the app schedules fewer cards then.

Divide your total due cards by a daily review target you can sustain, and that is roughly your number of days. Pausing new cards during recovery speeds it up. Most people clear even a large backlog in one to two weeks of steady, capped daily sessions.

Do not touch reset, and do not reschedule everything. Open your deck options, find the change that caused the spike, and reverse it if you can. Then cap your reviews, pause new cards, spread the overdue pile with postpone, and knock out a steady number every day while a simple spreadsheet counts down the days to zero. The number that scared you this morning is just a queue, and a queue always empties when you stop feeding it and start clearing it.