Minified React error React Origin: On your device Last updated 14 Oct 2026

Error: Minified React error #31; visit https://react.dev/errors/31 for the full message

A production React build threw an error whose message was shortened to a number.

Exact message you may see Minified React errorvisit https://react.dev/errorsvisit https://reactjs.org/docs/error-decoder.html
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Seen on: React

Meaning

Production builds strip messages. The URL decodes the full message; reproduce in development to get the full error and component stack.

Common causes

  • Same root causes as development errors (invalid child, hooks, hydration)
  • Production-only differences (env vars, data)

⚡ Quick fix

  1. Open the URL in the message to read the full text
  2. Reproduce with a development build
  3. Use source maps in your error monitoring

Detailed fix by platform

React

  1. Common numbers: #31 objects as child, #130 invalid element type, #418/#423/#425 hydration mismatches

How to diagnose

  1. Number — Which error code?
  2. Reproduce — Same in development?

🔧 Still not fixed?

Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:

Where this error sits

Origin: On your device. Errors that are often confused with or caused by this one (click to open):

Adjacent JSX elements — Adjacent JSX elements must be wrapped in an enclosing tag. Did you want a JSX fragment <>...</>? (React)Adjacent JSX elementscross-origin error — Error: A cross-origin error was thrown. React doesn't have access to the actual error object in development. (React)cross-origin errorHydration failed — Error: Hydration failed because the initial UI does not match what was rendered on the server (React)Hydration failednot wrapped in act — Warning: An update to Component inside a test was not wrapped in act(...) (React)not wrapped in actObjects are not valid as a React child — Error: Objects are not valid as a React child (React)Objects are not valid…setState during render — Warning: Cannot update a component (`Parent`) while rendering a different component (`Child`) (React)setState during renderuncontrolled to controlled — Warning: A component is changing an uncontrolled input to be controlled (React)uncontrolled to contr…Minified …

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