For power users

CLI Reference

The convertessa command gives you the full conversion engine from the terminal. Same formats, same quality controls, no GUI required.

Basic usage

Pass one or more input files and specify the target format with --to:

zsh
# Single file
$ convertessa photo.heic --to jpg
photo.jpg · 1.2 MB · 0.4s
 
# Multiple files
$ convertessa a.heic b.heic c.heic --to avif
3 files converted · 1.2s
 
# Glob pattern with output directory
$ convertessa ./photos/*.heic --to jpg -o ~/Desktop/converted
24 files converted · 5.2s

Global flags

FlagTypeDefaultDescription
--to <format>string Target format. Required. Case-insensitive — jpg, JPG, and jpeg all work.
-o, --output <path>pathalongside input Output file (single input) or directory (multiple inputs; created if missing). Default: same directory as the input, same name with the new extension.
--quality <value>0–100 or presetmax Output quality for lossy formats (JPEG, WebP, AVIF, MP3, …). Presets: web (60) | balanced (80) | high (90) | max (100). Ignored for lossless formats.
--strip-metadataflagkeep Strip metadata (EXIF/GPS, ID3 tags, container tags) from the output file.
--forceflagrefuse Overwrite existing output files. By default the CLI refuses and fails that file rather than silently overwriting.
--quietflagfalse Suppress all output except errors.
--debugflagfalse Print per-file pipeline detail (resolved paths, engine route, full errors) to stderr. Cannot be combined with --quiet.
--versionflag Print the Convertessa version and exit.
--helpflag Print usage and exit.

Formats & targets

The CLI supports the same formats as the app. See the conversion explorer on the homepage — pick an input format and see every output it supports.

Format identifiers are case-insensitive and match file extensions: use jpg or jpeg, mkv, 7z, etc. Run convertessa targets <file> to list every format a specific file can convert to, or convertessa suggestions-json to print the full suggestion table.

Examples

Extract audio from a video file:

zsh
$ convertessa interview.mov --to mp3 --quality balanced
interview.mp3 · 18.4 MB · 3.1s

Batch convert images for the web:

zsh
$ convertessa ./assets/*.png --to avif --quality 75 -o ./dist/images
48 files converted · 9.6s

Convert a Word document to Markdown:

zsh
$ convertessa report.docx --to md
report.md · 42 KB · 0.8s

Convert an EPUB for a Kindle:

zsh
$ convertessa book.epub --to mobi
book.mobi · 2.1 MB · 1.2s

Debug a conversion:

zsh
$ convertessa photo.heic --to jpg --quality 90 --debug
[debug] input: /Users/dale/photo.heic (heic, 3.4 MB)
[debug] route: LibVipsImageEngine → jpeg, quality 90
[debug] output: /Users/dale/photo.jpg
photo.jpg · 1.2 MB · 0.4s