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Fallow provides a one-command migration path from knip. Your existing configuration is automatically translated, so you can start running fallow in minutes.

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Migration workflow

1

Preview the migration

Run fallow migrate --dry-run to see the generated config without writing anything:
fallow migrate --dry-run
Fallow searches for: knip.json, knip.jsonc, .knip.json, .knip.jsonc, and the knip field in package.json.
$ fallow migrate --dry-run
Detected knip config: knip.json

Migrating settings:
  entry          → entry: ["src/index.ts", "src/cli.ts"]
  project        → (inverted to ignorePatterns)
  ignore         → ignorePatterns: ["**/*.generated.ts"]
  ignoreDeps     → ignoreDependencies: ["@types/node"]

⚠ Cannot migrate:
  ignoreBinaries → not applicable in fallow

Would write: .fallowrc.json
Run without --dry-run to write the config.
2

Generate the config

Once you’re happy with the preview, run the migration:
fallow migrate            # Write .fallowrc.json
fallow migrate --toml     # Or output as fallow.toml
3

Review the config

Open the generated config and verify the translated entry points, ignore patterns, and plugin mappings. Warnings are shown for any fields that couldn’t be migrated automatically.
4

Run fallow check

Run your first analysis and compare results against knip:
fallow check

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What gets migrated

knipfallow
entryentry
projectignorePatterns (inverted)
ignoreignorePatterns
ignoreDependenciesignoreDependencies
ignoreBinaries— (not applicable)
Plugin configsClosest fallow plugin equivalent

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Comparison

Fallow is a Rust-native standalone binary. No Node.js runtime, no JIT warmup, no garbage collection pauses.
Metricfallowknip
Speed vs knip v53—36x fasterBaseline
Speed vs knip v62—14x fasterBaseline
Memory usage3—15x lessBaseline
Runtime dependencyNone (standalone binary)Node.js
CI setupDownload binaryInstall Node + npm dependencies

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Key differences

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No runtime dependency

Fallow is a standalone binary. No Node.js runtime required, which means faster CI setup and no dependency conflicts.

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See also

Custom plugins

Build plugins for frameworks fallow doesn’t cover yet.

fallow migrate

Full CLI reference for the migrate command.