Letter Span Memory Test and Game

Cognitive Span Test

Letter Span

What this measures. Letter span is a classic test of short‑term (working) memory. You'll see a string of letters flash one at a time, then have to type them back. Get it right and the string grows by one letter; get it wrong and the session ends, recording the longest string you handled — your span.

Forward vs. backward. Forward span asks for the letters in the order you saw them. Backward span asks for them in reverse order, which leans harder on manipulating information in your head, not just holding it — most people score noticeably lower on it.

Set your options below, then press Begin Session. Your results and history are kept at the bottom of the page.

1Settings

Mode

Type the letters in the order shown.

Start length

4

Letters in the first sequence (2–9).

Show speed

How long each letter stays on screen.

Exclude confusions

On

Excluding: I, L, O, Q, S, Z

2Test

Ready when you are Choose your settings above, then press Begin Session.

Press Enter to submit your answer. Letters are automatically capitalized.

3Stats & results

–

Best forward span

–

Best backward span

0

Sessions played

–

Overall accuracy

Current session ladder

No session in progress yet.

Session history

When	Mode	Start	Speed	A–Z set	Span reached	Trials
No sessions yet — your results will appear here.

Digit Span Memory Game

SPAN // digit recall instrument

READY

Mode

Starting length

3

Speed

Enter the sequence

Session ended

0

longest span recalled correctly

Session history

No sessions recorded yet in this browser.

Digits are generated locally each round. Stats are stored in this browser only.

N-Back Trainer - Working memory / cognitive training

Working memory / cognitive training

N-Back Trainer

On every trial a square lights up on the grid (and, in audio modes, a letter is spoken). Your job: decide whether the current stimulus matches the one shown N steps back in the sequence. Press match as soon as you notice a repeat — scoring below tracks hits, misses, and false alarms in real time.

Setup

N-Level

Speed

Mode

Trials

20

Sound cues

Spoken letters on

TRIAL 0/20 N = 1 VISUAL

Session results

Run a session to see your hit rate, false alarms, and reaction time here.

Trial-by-trial trace

Hit Miss False alarm Correct rejection

N-back difficulty comes from load, not speed — if 2-back feels easy, raise N before you raise speed.
Runs entirely in your browser · no data leaves this page.

Help yourself learn/memorize 50 terms from Krebs Cycle

Krebs Cycle Mastery (SM2 Algorithm)

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Rate your memory performance:

🎉 Session Complete!

Excellent work. All pending components have been optimized via the SM-2 engine. Check back tomorrow for your next scheduled interval review.

Some important features of this post are:

• The SM-2 Spaced Repetition Engine: No more useless cramming. The built-in SuperMemo-2 algorithm tracks your memory strength and schedules your reviews at the exact mathematical moment you’re about to forget.
• 50 High-Yield Cloze Flashcards: Interactive, fill-in-the-blank prompts covering everything from irreversible checkpoints and cofactors (like TPP and biotin) to metabolic poisons (fluoroacetate and arsenite).
• 6-Tier Precision Grading: Rate your recall from 0 (Blank) to 5 (Perfect) to dynamically customize your learning curve.
• Seamless Progress Tracking: Features a built-in progress bar and automated local storage, meaning it saves your exact algorithmic memory weights so you can pick right up tomorrow.

N.B.: Kindly inform in case of any errors or mistakes in this post.