Pngyu

Free plan MacWindows

What Pngyu is

Pngyu is a free desktop application for compressing PNG images in batches on macOS and Windows. It uses pngquant to perform lossy compression, converting 24-bit or 32-bit full-color PNG files into 8-bit indexed color. Drag multiple files into the app and choose Compress Start to process them together. Unless changed, compressed files overwrite the originals. Output Option can be set to Custom for a different destination or filename, while Compress Option can be set to Custom for detailed settings. Selecting a file and choosing Preview opens a result window using the current settings. Because color reduction cannot be reversed, the maker advises backing up important images first. The homepage lists version 1.0.5 downloads for both supported platforms. Pngyu is described as a graphical front end for pngquant. The project uses the BSD license, while bundled pngquant binaries use GPL v3 or later.

Who it suits

Pngyu suits macOS or Windows users who need batch PNG compression with drag-and-drop input. It is also useful when custom output locations, detailed settings, or previews are needed.

What it does well

Free plan with no listed trial requirement
Batch processing for multiple PNG files
Custom output destination and filenames
Preview results before processing
Available for macOS and Windows

What to know first

Lossy compression permanently reduces color information
Compressed files overwrite originals by default
No API access is listed
macOS may require Open Anyway on first launch

Plans

Plan	Billed and limits	Price
Free	Free Software released under the BSD License	Free

As nukesaq88.github.io lists them, read 11 Oct 2026. The maker's own page has the final word.

Verdict

Pngyu provides a focused batch workflow for lossy PNG compression, with custom settings and previews. Back up important originals and review overwrite settings before starting.

Facts from Pngyu's own pages

API access: No · nukesaq88.github.io, 24 Sept 2026
Batch processing: Yes · nukesaq88.github.io, 24 Sept 2026
Batch workflow: Users can drag and drop multiple PNG files into the app and start compression with the Compress Start button. · nukesaq88.github.io, 11 Oct 2026
Compression engine: Pngyu uses pngquant as its compression engine. · nukesaq88.github.io, 11 Oct 2026
Compression modes: lossy · nukesaq88.github.io, 24 Sept 2026
Compression settings: The Compress Option can be changed to Custom for detailed compression settings. · nukesaq88.github.io, 11 Oct 2026
Default output: By default, compressed files overwrite the input files. · nukesaq88.github.io, 11 Oct 2026
Downloads: The homepage offers macOS and Windows versions, both listed as version 1.0.5. · nukesaq88.github.io, 11 Oct 2026
Free plan: Yes · nukesaq88.github.io, 24 Sept 2026
How compression works: pngquant converts 24-bit or 32-bit full-color PNG files to 8-bit indexed color. · nukesaq88.github.io, 11 Oct 2026
Integrations: The repository describes Pngyu as a front-end GUI application for pngquant. · github.com, 11 Oct 2026
Irreversible processing: Compression includes color reduction, so the original image cannot be restored from the compressed image; the maker advises backing up important files first. · nukesaq88.github.io, 11 Oct 2026
License: The project repository says Pngyu is distributed under the BSD license and that pre-built binaries include pngquant, licensed under GPL v3 or later. · github.com, 11 Oct 2026
macOS launch note: The maker says that because the app is independently distributed, macOS may require users to choose Open Anyway in Privacy & Security on first launch. · nukesaq88.github.io, 11 Oct 2026
Output settings: The Output Option can be changed to Custom to change the output destination or file name. · nukesaq88.github.io, 11 Oct 2026
Preview: Selecting a file and clicking Preview opens a window to check the result using the current settings. · nukesaq88.github.io, 11 Oct 2026
Purpose: Pngyu is a PNG image compression tool for batch compressing multiple PNG files. · nukesaq88.github.io, 11 Oct 2026
Support: Bug reports, feedback, and feature requests are accepted through GitHub Issues, Twitter, and email. · nukesaq88.github.io, 11 Oct 2026
Supported formats: PNG · nukesaq88.github.io, 24 Sept 2026

Where Pngyu stands on Freedom251

Image Compression Software#68 of 85