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bmux converts and compresses images without uploading them anywhere. The browser app does the work in your own tab; the CLI does the same job from a script, with no server involved either way.
The CLI uses sharp, so unlike the browser it can write every supported format and can keep EXIF metadata when you ask it to.

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Quickstart

1

Install

See Installation — the CLI is built from source for now.
2

Convert something

3

Check what you got

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The three commands

convert

Turn specific files into another format, with control over quality and size.

optimize

Run a whole directory through a preset without picking settings yourself.

inspect

Report what a file actually is, read from its contents rather than its name.

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Things that hold true everywhere

  • Originals are never overwritten. Colliding output names get a numeric suffix unless you choose otherwise with --collision.
  • Metadata is stripped by default. EXIF/XMP is removed unless you pass --preserve-metadata. Photos are still auto-rotated upright first.
  • A failed file doesn’t stop the rest. The batch finishes, the failures are listed, and the exit code is non-zero.
  • Nothing is uploaded. There is no server and no account. --dry-run will show you exactly what would be written before anything is.

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Colour output

Colour is used for status only — green for a saving, amber for a file that grew, red for a failure. It turns itself off when output isn’t a terminal, and it honours NO_COLOR: