Free Online N-Back Test: Measure Your Working Memory
N-Back is a classic working memory test that measures your memory updating ability and sustained attention. Determine if the current letter matches the one shown N steps back.
N-Back Working Memory Test
Test your working memory updating ability. Determine if the current letter matches the one shown N steps back.
Instructions:
- 1. A sequence of letters will appear on screen
- 2. Judge if the current letter matches the one N steps back
- 3. Press "Match" or A/Left Arrow for same
- 4. Press "No Match" or L/Right Arrow for different
Note: This test is for educational and self-assessment purposes only, not a medical diagnostic tool.
How It Works
Watch
Letters appear one by one
Compare
Compare with N steps back
Respond
Press Match or No Match
Continue
Maintain focus until the end
Test Features
Three Difficulty Levels
From 1-Back to 3-Back for different skill levels
Scientific Measurement
d' index based on signal detection theory
Cross-Platform
Works on desktop, tablet, and mobile devices
Privacy First
No registration required; data stays on your device
Track Progress
Monitor your improvement over time
Instant Feedback
Practice mode provides immediate feedback
d' Sensitivity Levels
d' values are affected by N level. Higher N levels typically produce lower d' values.
About the N-Back Test
Learn about the science, history, and real-world applications of this classic working memory test
What Is the N-Back Test?
The N-Back test is one of the most widely used experimental paradigms for measuring working memory in cognitive psychology. It requires participants to monitor a continuous sequence of stimuli (such as letters) and determine whether the current stimulus matches the one presented N positions back. For example, in a 2-Back task, you need to remember the last two letters and compare the current letter with the one shown two steps ago.
Working memory is a limited-capacity cognitive system responsible for temporarily storing and manipulating information. It forms the foundation for higher cognitive functions including reasoning, comprehension, learning, and decision-making. The N-Back task has become the gold standard for working memory research because it simultaneously requires sustained maintenance and dynamic updating of information — the core functions of working memory.
As the N value increases (from 1-Back to 3-Back), the demands on working memory rise significantly. Participants must not only remember previous stimuli but also continuously update memory contents while suppressing interference from no-longer-relevant information.
2-Back Task Demonstration
In a 2-Back task, the first 2 letters are just memorized. Starting from the 3rd, you judge whether each letter matches the one 2 steps back.
Historical Background
Wayne Kirchner's Innovation
Psychologist Wayne Kirchner first introduced the N-Back task paradigm to study the decay characteristics of short-term memory. This elegant experimental design quickly became a cornerstone tool in working memory research.
The Cognitive Training Boom
Jaeggi et al. published research claiming that dual N-Back training could improve fluid intelligence, sparking a worldwide wave of cognitive training research and extensive academic debate.
Key Milestones
Scientific Principles
Working Memory Model
According to Baddeley's working memory model, the N-Back task primarily relies on the central executive to coordinate maintenance, updating, and inhibition of information, while the phonological loop handles short-term storage of letter information.
Signal Detection Theory
d' is calculated based on signal detection theory, converting hit rate and false alarm rate into the difference between z-scores of the standard normal distribution. This method eliminates response bias, providing a pure measure of true discrimination ability.
Neural Mechanisms
fMRI studies show that the N-Back task activates the dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex, and parietal regions. Activity in these areas increases as the N value rises.
Individual Differences
N-Back performance shows significant individual variation, closely linked to fluid intelligence, attentional control, and age. Young adults typically perform best, and training effects vary between individuals.
Application Fields
Cognitive Psychology Research
Studying working memory capacity, attentional control, and information processing
Clinical Assessment
Evaluating cognitive function in ADHD, schizophrenia, traumatic brain injury, and more
Cognitive Training
Used as a working memory training tool to explore cognitive plasticity
Aging Research
Tracking age-related cognitive changes and cognitive reserve
Working Memory in Daily Life
Academic Performance
Understanding complex texts requires maintaining multiple concepts simultaneously; mental arithmetic requires storing intermediate results. Working memory is a core predictor of academic success.
Reading Comprehension
Reading requires remembering earlier content while processing new information. Working memory capacity directly affects understanding of complex sentences and passages.
Professional Development
Project management, debugging code, data analysis, and other professional activities heavily rely on working memory to process multiple information streams.
Social Interaction
Following conversation topics, remembering others' viewpoints, and understanding humor and sarcasm all require working memory support.
Healthy Aging
Working memory is one of the first cognitive functions affected by age. Staying cognitively active helps maintain independent living abilities.
Sports & Competition
Quick decision-making, tactical analysis, and anticipation in competitive activities require working memory to process and integrate dynamic information in real time.
Test Tips & Strategies
Verbal Rehearsal Strategy
Silently rehearse the last N letters in sequence (e.g., "H-T" for 2-Back), replacing the oldest letter each time. This is the most effective maintenance strategy.
Maintain a Steady Pace
Don't rush to judge the instant a letter appears. Use the full response window and maintain a consistent rhythm to reduce errors.
Avoid Overthinking
If you make a mistake, don't dwell on it. Immediately refocus on the current task — excessive reflection consumes precious working memory resources.
Progress Gradually
Start with 1-Back to learn the rhythm. Only increase the N level after consistently achieving d' > 2.5. Attempting high difficulty too early can lead to frustration.
Frequently Asked Questions
Common questions about the N-Back test
Important Notice & Disclaimer
Working memory ability varies between individuals and is affected by age, educational background, cognitive state, and other factors. Do not over-interpret a single test result — the average of multiple tests is more meaningful. N-Back performance improves with practice, reflecting increased task familiarity.
Disclaimer: This test is for cognitive practice and educational purposes only and does not serve as a medical diagnosis or treatment tool. Test results cannot replace professional medical evaluation or mental health diagnosis. If you have concerns about cognitive function or mental health, please consult a qualified physician or mental health professional.
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