Critical Thinking Tools
Four tools that read an argument and tell you what is wrong with it. Every one shows its working, so you can check the reasoning rather than take its word.
Fallacy Finder
Paste an argument. It quotes the exact sentence at fault, names the fallacy, and explains why that move does not work.
- Quotes the passage, never just the label
- Links through to the full explanation
- 750 characters free, 4,000 on Pro
Real output. The quoted spans are what make it checkable — you can disagree with it.
Bias Checker
The same treatment for the cognitive biases in the library — the ones that shape an argument before anybody states it.
- Every bias links to its own entry
- Says what the bias leaves out, not just its name
- Works on your own writing or someone else’s
Writing Lab
Write in it, and it marks the weak reasoning where it sits — then offers a rewrite you can accept in one click.
- Highlights the passage in place, not in a list
- Suggests a rewrite; keeps your version in history
- A reasoning score that moves as you edit
- Unlimited documents, export to PDF or Word
Cancel any time. The free tools stay free.
The marked passage and the rewrite card are the whole pitch.
Fallacy Quiz
Over a thousand questions across every entry in the library. Ten at a time, with the reasoning shown after each answer.
- 1,032 questions, easy through hard
- Explains why the answer is the answer
- Tracks which fallacies you keep missing
Educator Resources
Lesson plans, worksheets, slide decks and classroom activities for teaching critical thinking and logical fallacies.
Using these at work?
Two guides to getting more out of them, written for the people who use them daily.
Create a free account
Sign up to save your quiz scores, track progress, and access all free tools.