APNG File

What are APNG files and how to open them

Are you having problems opening an APNG file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your APNG files.

What is an APNG file?

An .APNG file is an Animated Portable Network Graphics file.

Animated Portable Network Graphics files store still images and animations using a frame-based method that builds on the standard Portable Network Graphics format. They are used when a graphic needs to show motion (for example, animated icons or effects on web pages) while preserving full-color detail and transparency, features that formats like GIF do not offer. Web browsers and imaging tools that support animated graphics typically write these files when creating animated content that requires higher fidelity than simpler formats allow.

These files are produced using specialized software or libraries that support the APNG specification. Creation involves combining a sequence of frames - each recording full color and alpha transparency - along with timing and display instructions. The file also includes a "default image" which non-APNG-aware viewers show (often the first frame). Decoders that support APNG read the animation control (acTL), frame control (fcTL), and frame data (fdAT) chunks to display the full animated sequence seamlessly. Editors of APNG must generate these specific chunks correctly, and viewers of the format show the animation by compositing frames over time.

Internally, these files begin with the standard PNG file signature and include the usual critical chunks like IHDR (image header), IDAT (image data), and IEND (image end), just like ordinary PNG. Additional chunks acTL (animation control), fcTL (frame control), and fdAT (frame data) appear to manage the number of frames, looping behavior, frame timing, and placement. Byte signatures include the PNG signature at the start, the acTL chunk before any IDAT(s), and frame control and data chunk types: fcTL, fdAT.

How to open APNG files

Important: Different programs may use files with the APNG file extension for different purposes, so unless you are sure which format your APNG file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested seven different APNG openers which you will find listed below.

Last updated: August 18, 2026

Various apps that use files with this extension

These apps are known to open certain types of APNG files. Remember, different programs may use APNG files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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File.org helps thousands of users every day, and we would love to hear from you if you have additional information about APNG file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.