OptiPNG is a PNG optimizer that recompresses image files to a smaller size, without losing any information. This program also converts external formats (BMP, GIF, PNM and TIFF) to optimized PNG, and performs PNG integrity checks, corrections, metadata recovery and pixmap-to-PNG conversion.
OptiPNG optimizes PNG files, i.e. reduce their size to a minimum, without losing semantic information. In addition, this program shall perform a suite of auxiliary functions like integrity checks,
The optimization attempts are not guaranteed to succeed. Valid PNG files that cannot be optimized by this program are normally left intact; their size will not grow. The user may request to override this default behavior.
Key Features
- Lossless compression tool for PNG images. It can also convert non-PNG files (BMP, GIF, PNM and TIFF) into compressed PNG file.
- Encoding and optimization options:
- Select the optimization level:
- The optimization level 0 enables a set of optimization operations that require minimal effort. There will be no changes to image attributes like bit depth or color type, and no recompression of existing IDAT datastreams.
- The optimization level 1 enables a single IDAT compression trial. The trial chosen is what OptiPNG thinks it’s probably the most effective.
- The optimization levels 2 and higher enable multiple IDAT compression trials; the higher the level, the more trials.
- Filters – select the PNG delta filters. The filter values 0, 1, 2, 3 and 4 indicate static filtering, and correspond to the standard PNG filter codes (None, Left, Up, Average and Paeth, respectively). The filter value 5 indicates adaptive filtering, whose effect is defined by the libpng library used by OptiPNG.
- Other options are available.
- Select the optimization level:
- Error recovery.
- Simulation mode – performs the trials but doesn’t create output files.
Website: optipng.sourceforge.net
Support:
Developer: Cosmin Truta and contributors
License: zlib license
OptiPNG is written in C. Learn C with our recommended free books and free tutorials.
Related Software
| Console Based Image Compression Tools | |
|---|---|
| MozJPEG | Mozilla JPEG Encoder Project |
| pngquant | Utility and a library for lossy compression of PNG images |
| SVGO | Node.js library and command-line application for optimizing SVG files |
| Oxipng | Multithreaded PNG optimizer, forked from Optipng |
| libjxl | Reference implementation of JPEG XL |
| libjpeg-turbo | JPEG image codec |
| QOI | The Quite OK Image Format |
| YOGA | Yummy Optimizer for Gorgeous Assets |
| pngcrush | Optimizer for PNG files |
| jpegoptim | Optimize JPEG files. Lossless and lossy compression available |
| OptiPNG | Advanced PNG optimizer |
| Guetzli | Perceptual JPEG encoder with excellent compression density at high quality |
| ECT | Fast and effective C++ file optimizer |
| Crunch | Lossy PNG image file optimization |
| zopflipng | PNG optimisation tool using zopfli |
| JPEG Archive | Utilities for archive JPEGs for long term storage |
| optimizt | CLI image optimization tool |
| picopt | Multi format lossless image optimize |
| tinifier | CLI tool for compressing images using the TinyPNG API |
Read our verdict in the software roundup.
 Explore our carefully curated directory of recommended free and open source software, covering every major software category.The directory forms part of our extensive collection of articles for Linux enthusiasts. It includes hundreds of detailed reviews, together with free and open source alternatives to proprietary software from companies such as Google, Microsoft, Apple, Adobe, IBM, Cisco, Oracle, and Autodesk. LinuxLinks also covers interesting projects worth exploring, Linux-compatible hardware, free programming books and tutorials, and much more. Know a useful free and open source Linux application that we haven’t covered? Tell us about it using our submission form. |
Please read our Comment Policy before commenting.