In a legacy React Native app flooded with warnings, what do LogBox.ignoreLogs and LogBox.ignoreAllLogs each hide, and what do they leave visible?

middleshould knowfreq 38%

answer

substring string or RegExp patterns
patterns apply to errors too
ignoreAllLogs: notifications only
full screen still shows uncaught errors
console and release builds unaffected

basics

~20 s

LogBox.ignoreLogs drops LogBox entries matching a substring or RegExp, at any level, errors included. LogBox.ignoreAllLogs turns off LogBox notifications, but uncaught errors still open full screen. Neither removes messages from the console, and both do nothing in release builds.

solid answer

~40 s

LogBox.ignoreLogs takes strings, matched as substrings, and regular expressions, and LogBox drops any log whose message matches, whatever its level, so a broad pattern can hide a real error. LogBox.ignoreAllLogs() disables LogBox notifications for warnings and errors; the docs suggest it for product demos, and uncaught errors still open the full-screen view. Neither touches the console: DevTools still receives every message, and in release builds both calls are no-ops. The old YellowBox API and console.ignoredYellowBox were removed in 0.79. For a noisy legacy app I fix the warnings we own, ignore only exact messages from third-party code we cannot fix, with a comment saying why, and never commit ignoreAllLogs.

`LogBox.ignoreLogs` takes strings, matched as substrings, and regular expressions, and LogBox drops any log whose message matches, whatever its level, so a broad pattern can hide a real error. `LogBox.ignoreAllLogs()` disables LogBox notifications for warnings and errors; the docs suggest it for product demos, and uncaught errors still open the full-screen view. Neither touches the console: DevTools still receives every message, and in release builds both calls are no-ops. The old `YellowBox` API and `console.ignoredYellowBox` were removed in 0.79. For a noisy legacy app I fix the warnings we own, ignore only exact messages from third-party code we cannot fix, with a comment saying why, and never commit `ignoreAllLogs`.

code

tsx · 7 lines

tsx

import { LogBox } from 'react-native';

// Too broad: also hides real errors whose message contains 'Error'
LogBox.ignoreLogs([/Error/]);

// Narrow: one known third-party message, with a reason
LogBox.ignoreLogs(['LegacyBarcodeView: prop `torchMode` is deprecated']);

go deeper

for a junior

Recall that ignoreLogs hides specific messages and ignoreAllLogs hides LogBox notifications, and that both are development-only.

for a middle

Explain why ignores are dangerous: patterns match errors too, the console still shows everything, and a hidden warning is a hidden upgrade signal.

for a senior

Show a policy for a noisy legacy app: fix owned warnings, narrowly ignore unfixable third-party ones with a reason, and review ignores on each upgrade.

for a principal

Treat warning hygiene as upgrade readiness, and decide who owns the ignore list and when entries must be justified or removed.

The situation

A legacy loyalty-card app on React Native produces a flood of development warnings: deprecated lifecycle methods in old class components, a barcode-scanner library warning about props, a navigation library complaining about non-serialisable params. Someone proposes making it go away with one line. Which line, and what does it cost?

The two LogBox silencers

LogBox from react-native offers two calls, usually placed at the top of the entry file so they run before the first log:

Call	What it does	What it does not do
`LogBox.ignoreLogs(patterns)`	drops any LogBox entry whose message matches a pattern: a string matches as a substring, a RegExp is tested against the message	remove anything from the console; fix the cause
`LogBox.ignoreAllLogs(value?)`	turns off LogBox notifications for warnings and errors (`true` when called with no argument, `false` to re-enable)	stop uncaught errors from opening the full-screen view

Details that matter:

Patterns apply to every level. LogBox checks ignore patterns before storing any log — warnings, errors and exceptions alike. A broad pattern such as /Error/ or 'undefined' can therefore swallow a real error, and even keep an uncaught exception out of LogBox.
ignoreAllLogs is documented for demos. The React Native docs suggest it for situations such as product demos; the source notes that it only disables notifications and uncaught errors still open full screen.
The console still has everything. LogBox forwards warnings to the original console.warn before filtering, and errors reach the console too, so DevTools shows them regardless.
Release builds are unaffected. In a release build LogBox is not installed and both calls do nothing.

There is also a lower-level switch: setting console.reportErrorsAsExceptions = false stops React Native from treating console.error as an exception report at all. It is another way to hide a real signal and needs the same scrutiny.

Removed APIs in old code

Legacy code may still call the YellowBox module or set console.ignoredYellowBox. Both were deprecated for years and removed in React Native 0.79; the replacement is LogBox.ignoreLogs. An upgrade that fails on a YellowBox import is telling you to migrate, not to shim.

What silencing hides

Real regressions. A new warning with a message similar to an ignored one never gets seen.
Upgrade signals. Deprecation warnings are the schedule for the next upgrade; hiding them turns a planned migration into a surprise.
Errors, if the pattern is broad. Because patterns apply to errors too, the wrong regex can hide the one error that explains a bug.
Other developers' context. A global ignore in the entry file silences warnings for everyone on the team, including in code they are writing today.

A defensible approach for the loyalty-card app

Fix what you own: convert the deprecated lifecycles, pass serialisable navigation params.
Narrowly ignore what you cannot fix: an exact message substring from the third-party barcode library, with a comment naming the library version and a link to its issue.
Never ignoreAllLogs in committed code outside a demo branch.
Review ignores on every upgrade, deleting those whose cause is gone.
Triage in the DevTools Console, which shows the unfiltered stream.

tsx

// index.ts
import { LogBox } from 'react-native';

// A third-party barcode view warns about its own prop; remove after upgrading it.
LogBox.ignoreLogs(['LegacyBarcodeView: prop `torchMode` is deprecated']);

## The situation A legacy **loyalty-card app** on React Native produces a flood of development warnings: deprecated lifecycle methods in old class components, a barcode-scanner library warning about props, a navigation library complaining about non-serialisable params. Someone proposes making it go away with one line. Which line, and what does it cost? ## The two LogBox silencers `LogBox` from `react-native` offers two calls, usually placed at the top of the entry file so they run before the first log: | Call | What it does | What it does not do | |---|---|---| | `LogBox.ignoreLogs(patterns)` | drops any LogBox entry whose message matches a pattern: a **string** matches as a substring, a **RegExp** is tested against the message | remove anything from the console; fix the cause | | `LogBox.ignoreAllLogs(value?)` | turns off LogBox notifications for warnings and errors (`true` when called with no argument, `false` to re-enable) | stop uncaught errors from opening the full-screen view | Details that matter: - **Patterns apply to every level.** LogBox checks ignore patterns before storing any log — warnings, errors and exceptions alike. A broad pattern such as `/Error/` or `'undefined'` can therefore swallow a real error, and even keep an uncaught exception out of LogBox. - **`ignoreAllLogs` is documented for demos.** The React Native docs suggest it for situations such as product demos; the source notes that it only disables notifications and uncaught errors still open full screen. - **The console still has everything.** LogBox forwards warnings to the original `console.warn` before filtering, and errors reach the console too, so DevTools shows them regardless. - **Release builds are unaffected.** In a release build LogBox is not installed and both calls do nothing. There is also a lower-level switch: setting `console.reportErrorsAsExceptions = false` stops React Native from treating `console.error` as an exception report at all. It is another way to hide a real signal and needs the same scrutiny. ## Removed APIs in old code Legacy code may still call the **YellowBox** module or set `console.ignoredYellowBox`. Both were deprecated for years and **removed in React Native 0.79**; the replacement is `LogBox.ignoreLogs`. An upgrade that fails on a `YellowBox` import is telling you to migrate, not to shim. ## What silencing hides 1. **Real regressions.** A new warning with a message similar to an ignored one never gets seen. 2. **Upgrade signals.** Deprecation warnings are the schedule for the next upgrade; hiding them turns a planned migration into a surprise. 3. **Errors, if the pattern is broad.** Because patterns apply to errors too, the wrong regex can hide the one error that explains a bug. 4. **Other developers' context.** A global ignore in the entry file silences warnings for everyone on the team, including in code they are writing today. ## A defensible approach for the loyalty-card app - **Fix what you own**: convert the deprecated lifecycles, pass serialisable navigation params. - **Narrowly ignore what you cannot fix**: an exact message substring from the third-party barcode library, with a comment naming the library version and a link to its issue. - **Never `ignoreAllLogs`** in committed code outside a demo branch. - **Review ignores on every upgrade**, deleting those whose cause is gone. - **Triage in the DevTools Console**, which shows the unfiltered stream. ```tsx // index.ts import { LogBox } from 'react-native'; // A third-party barcode view warns about its own prop; remove after upgrading it. LogBox.ignoreLogs(['LegacyBarcodeView: prop `torchMode` is deprecated']); ```

Where should LogBox.ignoreLogs be called in a React Native app, and why?
At module scope in the entry file or an early setup module, so the patterns are registered before the first logs arrive. Called inside a component, it runs only after that component renders, and earlier messages have already been shown.
A legacy React Native codebase fails to build after an upgrade because it imports YellowBox. What is the fix?
The `YellowBox` module and `console.ignoredYellowBox` were removed in React Native 0.79. Replace them with `LogBox.ignoreLogs` for the specific messages that still need ignoring, and treat the upgrade as a prompt to fix the underlying warnings.

Ignoring logs is taping over a warning light on a car's dashboard: the fault is still there, and a wide enough strip of tape covers the oil-pressure light along with the one you meant to hide.

saying these in an interview costs you the question

LogBox.ignoreLogs removes the messages from the console as well
Ignore patterns only ever apply to warnings, never to errors
LogBox.ignoreAllLogs also suppresses the full-screen view for uncaught errors
Ignoring logs in development also silences them in production
Calling LogBox.ignoreAllLogs in the entry file is standard practice

In a legacy React Native app flooded with warnings, what do LogBox.ignoreLogs and LogBox.ignoreAllLogs each hide, and what do they leave visible?

§ answer

basics

solid answer

code

§ go deeper

▾level notes4 levels

▾deep dive~3 min

The situation

The two LogBox silencers

Removed APIs in old code

What silencing hides

A defensible approach for the loyalty-card app

▾common follow-ups2 questions

▾analogy~20 s

▾red flags5 flags

The situation

The two LogBox silencers

Removed APIs in old code

What silencing hides

A defensible approach for the loyalty-card app

answer

go deeper