Underpressured

Compress and resize images

Only for Mac

Free

Mac

Compress and resize a whole folder of images at once. Choose a preset for format, quality, and size, then see how much smaller each file got. It all runs on your Mac. Underpressured is a free, open-source Mac app that compresses, converts, and resizes images. Drop in a whole folder or a single image, pick your settings, and it handles them all at once. You can save your settings as a preset for next time and choose where the results go. When it's done, you can compare the file sizes before and after. Everything runs on your Mac. Nothing gets uploaded, there's no account to create, and the app collects no analytics. PRESETS THAT REMEMBER YOUR SETTINGS • Save as JPEG or PNG, or keep the original format • Set the quality anywhere from 0 to 100, or go lossless • Cap the width, the height, or the longer side. The aspect ratio stays put, and nothing ever gets upscaled • Keep metadata like EXIF, GPS, IPTC, and XMP, or strip it out • Four presets come built in: Balanced (convert to JPEG), Web, Small, and Screenshots (convert to PNG). Edit, duplicate, and reorder them, and keep up to 20 • Jump between presets with Command-1 through Command-9. Changed one by mistake? Undo has your back WHERE THE SMALLER FILES GO • Replace the originals. If you want a safety net, Underpressured can move each original to the Trash instead of overwriting it • Or export copies to a folder you pick. Dropped folders keep their subfolders • Underpressured never overwrites an existing file. It adds a suffix instead, so you get photo-2.jpg • Saved files keep the source's dates, Finder tags, and permissions • Each result goes to a temporary file first, and Underpressured checks that the source hasn't changed before it saves FORMATS Opens JPEG, PNG, HEIC, WebP, TIFF, AVIF, and JPEG XL. Saves JPEG and PNG. GIF, RAW, animated images, and multi-page TIFFs aren't supported. UNDER THE HOOD • jpegli writes progressive JPEGs. In lossless mode, JPEGs get rewritten without re-encoding their pixel data • Palette reduction makes lossy PNGs smaller, and it won't drop below a quality floor • oxipng squeezes lossless PNGs without changing a single pixel • Resizing uses a Lanczos filter in linear light • Color profiles come along for the ride. CMYK images convert to sRGB when re-encoded IT KNOWS WHEN TO STOP • If compressing would make a file bigger, the original stays and the image is marked as already optimal • Images already optimized with the same settings get skipped • Hidden files, packages, and anything that isn't an image are left alone MADE FOR THE MAC • Drop files or folders onto the window or the Dock icon, use File > Open, or pick Open With in Finder • Preview results with Quick Look, open them, or show them in Finder • Filter results by optimized, skipped, failed, or cancelled • Changed your mind? You can cancel the whole queue and cleans up any half-written files • Your Mac stays awake while the queue runs, and a notification lets you know when a batch finishes in the background • Speaks English, Spanish, Brazilian Portuguese, German, French, Arabic, Japanese, and Simplified Chinese Underpressured is free and open source under the MIT license.

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The developer, Andrei Dementev, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

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    Information

    Seller
    Andrei Dementev
    Size
    3 MB
    Category
    Graphics & Design
    Compatibility
    Requires macOS 27.0 or later and a Mac with Apple M1 chip or later.
    • Mac
      Requires macOS 27.0 or later and a Mac with Apple M1 chip or later.
    Languages
    English and 7 more
    • English, Arabic, French, German, Japanese, Portuguese, Simplified Chinese, Spanish
    Age Rating
    4+
    Copyright
    © 2026 Andrei Dementev
  • Developer Website
  • Privacy Policy