PngOptimizer v2.5.1 Updated

billon on 14 Feb 2017
  • 312KB (uncompressed)
  • Released on 13 Feb 2017
  • Suggested by Replika

PngOptimizer is an easy-to-use program to compress common graphics formats to PNG format with no quality difference. Files can be added one at a time or in batch to the program icon or window. Images can also come from the clipboard by pressing CTRL+V while the application is in focus. Graphics formats supported include BMP, GIF, TGA, as well as further compressesing PNG files. Animated GIF and PNG files (APNG) are also supported. Size decrease for PNG files varies widely on the original editor, but GIF and BMP conversions can be as much as 40% and 95% respectively.

Cross-platform with clients available for Linux. A CLI version is available.

Alternatively, PngOptimizer Portable automatically switches between 32-bit and 64-bit and adjusts the screenshots path.

System Requirements: WinXP / Vista / Win7 / Win8 / Win10
Writes settings to: Application folder
Stealth: ? Yes
Unicode support: Yes
Path portability: No
License: GPL
How to extract:
  1. Download the ZIP package and extract to a folder of your choice
  2. In the same folder, create a text file called PngOptimizer.ini
  3. Launch PngOptimizer.exe

Optionally, to save images from the clipboard to the PngOptimizer application folder, right-click on the window and select Custom for the target directory and enter a period (.) in the box below.
Similar/alternative apps: FileOptimizer
What's new?
  • Fixed: window position would be always centered instead of being restored to the previous position.

13 comments on PngOptimizer  The Portable Freeware Collection Latest Entries Feed

Jan 2009-02-08 09:37

It takes forever to start this app. On windows XP.

Teo 2009-02-20 00:41

Agree, 65% processor time and start after 2 minutes on P4/2GHz? No way, this PngOptimizer must be optimized.

Jon Wright 2009-02-20 12:43

Just downloaded 1.8 - same problem. Nothing's appeared and processor is using 100% on one core. Three minutes now so it'll have to be killed.

tun 2009-02-21 09:10

If we don't create ini file, it is working fine.

tun 2009-02-21 09:15

Create the 'PngOptimizer.ini' with the following content and save in 'UTF-8' format

================ start ===============
; PngOptimizer configuration file
; This file is encoded in UTF-8

BackupOldPngFiles = 1
KeepInterlacing = 0
KeepBackgroundColor = 0
AvoidGreyWithSimpleTransparency = 1

UseDefaultDir = 1
CustomDir =
MaximizeCompression = 1
AskForFileName = 0

X = 345
Y = 215
Width = 521
Height = 300
============== end =====================

Webfork 2009-11-11 20:06

Great program. Thanks tun for the ini config trick.

Paul 2011-05-10 01:01

.. with just a few random characters like the asdf example in 'PngOptimizer.ini' .. the new update works great on Win98 (or the whole ini template)


webfork 2011-11-03 17:35

This program is great for general PNG compression, but for web graphics that will see many downloads over time, I use RIOT (


webfork 2013-05-31 23:08

Note about the 2.3 update: definitely takes full advantage of multi-processor systems. I tested it on Win7x64 with an i7 quad core and it got very close to 90% (few programs can do that). Definitely a big speed bonus over time there and good to see those kind of optimizations in freeware.


billon 2014-05-28 02:41

From changelog: "Updated source code for Visual Studio 2012." Now it don't work on XP. Damn, i need previous version


billon 2014-05-30 06:56

Dev fix "Windows XP compatibility for 32 bits build" in new v. 2.41 for x86
x64 remain v. 2.4


Checker 2014-05-30 09:29

@ billon: Thanks ... and updated ;)


DarkShadow 2014-06-10 16:35

There is a v2.4.2 for x64 !


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