:: COMPARE ::
The short answer
Reductio ad Hitlerum names a FALLACY — X is bad because Nazis liked it. Godwin's law names a FREQUENCY. Conflating them is exactly the misreading Godwin spends his time correcting.
Side by side
| Aspect | Godwin's law | Reductio ad Hitlerum |
|---|---|---|
| Is a | Prediction | Fallacy |
| Says an argument is wrong | No | Yes |
| Ends the discussion | No | Should |
| Author's view | Misused constantly | Genuine error |
What each one means
As an online discussion grows longer, the probability of a comparison to Nazis or Hitler approaches one. The name is also widely used for a later rule — that whoever makes the comparison first has lost the argument — which Godwin himself rejects.
Full definition of Godwin's Law →The contrast above sets out how Reductio ad Hitlerum differs from Godwin's Law on the points that actually matter.