Free Online Flanker Test
A browser version of the Eriksen flanker task: five arrows appear in a row and you respond only to the middle one. The gap between your conflicting and non-conflicting trials is the flanker effect.
Flanker Test
Respond to the center arrow and ignore the ones beside it
Select Mode
How to play
- • Five symbols appear in a row. Only the middle arrow counts.
- • Tap Left or Right, or press the ← and → keys.
- • Answer as fast as you can without guessing.
How It Works
Look
Five symbols appear in a row. Only the arrow in the middle is your target.
Ignore
The four flanking symbols may point the same way, the opposite way, or be neutral dashes.
Respond
Tap Left or Right — or press the arrow keys — as fast as you can without guessing.
Compare
When time runs out, see how much the conflicting flankers cost you in milliseconds.
Test Features
Balanced Trial Mix
Congruent, incongruent and neutral trials are kept in equal proportion so the effect size stays stable
Classic Research Paradigm
A browser implementation of the arrow flanker task used in selective attention research since 1974
Keyboard or Touch
Arrow keys on desktop, large left and right buttons on phones — same task, same timing
Privacy First
No registration required. All data stays in your browser's local storage
Condition Breakdown
Separate reaction times for each condition, plus interference and facilitation split out
Reliability Flag
Sessions with too few correct trials per condition are marked provisional instead of reported as fact
About Selective Attention
What Does the Flanker Test Measure?
The flanker task probes selective attention — your ability to lock onto one thing and keep everything around it from steering your response. When the flanking arrows point the opposite way, your brain briefly prepares the wrong answer and has to override it. That override costs measurable milliseconds.
That cost is the flanker effect: mean reaction time on incongruent trials minus congruent trials. A smaller effect means the distracting arrows had less pull on you during this session. It describes performance under this site's rules and is not a standardized or clinically validated measure.
Adding neutral trials splits the effect in two: interference (how much the conflicting arrows slow you down relative to neutral) and facilitation (how much matching arrows speed you up). Two people with the same flanker effect can arrive at it through very different mixes of the two.
Scientific Principles
The Eriksen Flanker Task
In 1974, Barbara and Charles Eriksen showed that irrelevant letters beside a target letter slow identification when they call for a competing response. The paradigm became a standard tool for studying how attention is focused in space.
Response Competition
Attention does not switch off outside a narrow spotlight. Flanking arrows are processed far enough to activate their own response, so incongruent trials require suppressing a partially prepared action before the correct one can be released.
Conflict Monitoring
Influential work by Botvinick and colleagues proposes that the brain detects response conflict and recruits more control on the following trial. This is why performance after a hard trial often looks different from performance after an easy one.
Individual Differences
Effect sizes vary with age, alertness, practice, screen size and how fast someone chooses to answer. This site has no population norms and cannot evaluate attention ability, ADHD, or any clinical condition.
Brain Regions Involved
Attention research links conflict resolution in this task to a coordinated network of key areas:
Anterior Cingulate Cortex
Registers that two responses are competing and signals that more control is needed — the conflict detector of the network.
Dorsolateral Prefrontal Cortex
Holds the rule "respond to the centre only" active and biases processing toward the target when conflict is detected.
Posterior Parietal Cortex
Sets the spatial spotlight of attention and narrows it onto the middle position while the flankers push outward.
Applications
Attention Research
The flanker task is a core component of the Attention Network Test, which researchers use to separate alerting, orienting and executive control.
Clinical Research
Professionally administered conflict tasks appear in broader research batteries; this site cannot screen for ADHD or any other condition.
Developmental Research
Researchers track how conflict resolution changes across childhood and later life; a single online session cannot place anyone on such a trajectory.
Cognitive Training Research
Whether practice on conflict tasks transfers to everyday attention is actively debated; improvement here mainly reflects familiarity with this task.
Selective Attention in Daily Life
Staying on one line of text while movement and conversation surround you
Reacting to your own lane while signs, billboards and other cars compete for attention
Holding a task in mind while nearby screens and conversations pull at it
Tracking one player or one ball among many moving bodies
Clicking the right item in a crowded dashboard, spreadsheet or menu
Following one voice at a table where several people are talking at once
Task Strategies and Comparison Tips
Fixate the Centre
Keep your gaze parked where the middle arrow will appear instead of scanning the row — the flankers are never worth reading.
Do Not Trade Accuracy for Speed
Answering before you are sure does not shrink the flanker effect; it just moves the cost from time into errors.
Run Longer Sessions
Effect sizes are differences between two averages. The 60-second and 3-minute modes give far steadier numbers than a 30-second run.
Keep Conditions Fixed
Screen size, viewing distance, input method and alertness all shift reaction times. Comparable records need similar conditions.
Site-Defined Result Bands
Descriptive bands for the flanker effect in milliseconds, not population norms
Frequently Asked Questions
Common questions about the Flanker Test
Important Note
This flanker test is for educational and entertainment purposes only. It is not a standardized, norm-referenced, or clinically validated assessment, and should not be used to diagnose or rule out ADHD, attention disorders, or any other condition. If you have concerns about your attention or concentration, please consult a qualified healthcare professional.
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