Threshold‑Based Performance Hints vs Silent Builds: Which Keeps Noise Low?

Direct answer

Webpack’s performance.hints uses maxAssetSize and maxEntrypointSize thresholds (in bytes) to flag bundle regressions. Starting points for multi‑entry projects often need adjustment because source maps and hashed media inflate reported sizes beyond the defaults (250 kB assets, 400 kB entrypoints). Hints are active in production mode only; development builds typically suppress them regardless of configuration.

Likely explanation vs confirmed facts

• Likely: In multi‑entry or source‑map‑heavy builds, the default thresholds frequently fire for legitimate large assets—especially images, fonts and map files—creating ambient noise.
• Confirmed: Threshold values are plain byte numbers (e.g., 250000), not human‑readable strings. Webpack evaluates uncompressed sizes; gzipped transfer size may differ. The performance.assetFilter function is the supported hook to exclude asset types from the size check.

Calibration steps for your build

1. Run a production build and record each emitted warning’s asset name and byte count.
2. Add an assetFilter that returns false for extensions you wish to silence (e.g., .map, .woff, .ttf) while keeping .js entries checked.
3. Rebuild and verify that only JS‑related warnings remain. Adjust thresholds upward (e.g., 300 000–500 000 for assets, 600 000–1 000 000 for entrypoints) until false positives subside.
4. If a CI budget tool (size‑limit, bundlesize) enforces per‑file budgets, setting performance.hints: false is defensible; otherwise keep hints enabled to catch regressions early.

To determine whether your thresholds need upward adjustment, please share the uncompressed size range of your largest non‑JS asset. Assumes webpack 5+ where performance.hints configuration is stable.