Compare software

Efficient Compression Tool vs MozJPEG: catalog facts
Efficient Compression Tool	MozJPEG
Free Free and open source under the Apache 2.0 licence.	Free Free and open source under BSD-style, IJG and zlib licences.
Windows, Command line	Windows, Command line
Handles PNG, JPEG, GZIP and ZIP in one tool Adjustable levels to trade speed against file size	Smaller JPEG files that work in any JPEG decoder Includes cjpeg and djpeg command-line tools
Command-line only Limited to four file formats	Command-line only, with no graphical interface Encoding is slower than a standard encoder
Downloadable app	Downloadable app
Open source	Open source
License: Apache-2.0	License: BSD-3-Clause AND IJG AND Zlib
No account needed	No account needed
Works offline	Works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked October 2, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.