Photo Size Optimizer

Photo Size Optimizer is a Mac utility for shrinking and resizing image collections with one-click batch controls. It suits photographers, publishers, and anyone handling folders of mixed image files who wants a free desktop workflow. Its strongest case is straightforward bulk processing; users who need cross-platform access or highly granular editing should look elsewhere.

Overview

The app combines dimension-based resizing with compression designed to reduce file size without changing an image’s original resolution. Optimization is stated for PNG, JPG, and GIF files, while resizing supports more than 70 image formats. That distinction matters: a mixed-format folder can be resized broadly, but the headline compression behavior is confined to the three named formats.

Dragging a folder into the application starts processing immediately, and batches of hundreds of photos can be resized in one click. This is a practical fit for recurring export chores, website image preparation, or cleaning up a camera archive. It is less suitable when every file needs a different treatment or when a visual editor is required. The export flow asks before overwriting originals, providing a useful safeguard during large jobs.

Key features

Lossless and lossy compression

Lossless mode claims to save more than 20% of storage while retaining original resolution and quality. It is the prudent setting for archival images, client deliveries, or graphics where visible degradation is unacceptable, although the space reduction is comparatively modest. Lossy mode claims savings above 50% with minor quality loss. That makes it the better choice for email attachments, web uploads, and large personal libraries where storage and transfer speed outweigh pixel-perfect fidelity. “Minor” quality loss remains a trade-off, so important originals should be preserved separately.

Batch resizing and controls

Resizing is handled by dimensions, with quality controls available for output decisions. One-click processing and folder drops reduce repetitive work, while the overwrite prompt helps prevent accidental replacement of source files. The output list includes JPG, BMP, PNG, GIF, PDF, PSD, PNT, RGB, ARW, CRW, CR2, DNG, EPS, EXR, HDR, ICNS, ICO, JP2, JPE, JFIF, JPF, MPO, MAC, MRW and many other formats, giving broad flexibility for conversion-oriented batches.

Pricing

The free Photo Size Optimizer plan costs nothing, is billed Free, runs on Mac only, includes no in-app purchases, and has a 2.8 MB footprint. It is unusually direct for users who need basic bulk resizing and compression without a subscription or usage quota.

A separate Photo Size Optimizer entry shows an Original price of 29.99 USD, billed once as Original $ 29.99, also for Mac. The paid listing does not state additional capabilities, so the free plan is the logical starting point; pay only if that edition is the one you specifically need. There is no recurring renewal term to manage on either entry.

Platforms

Photo Size Optimizer is desktop software for macOS. The App Store requirement is macOS 10.6 or later, and there is no Windows, Linux, iOS, Android, or web version. Apple’s listing says the developer does not collect data from the app. EffectMatrix provides [email protected] for feedback and support.

Who it's for

Choose it for Mac-based batch work: photographers reducing a shoot, teams preparing image folders for publishing, or individuals reclaiming storage from large collections. Lossless processing serves quality-sensitive archives, while lossy processing favors web and sharing workflows. It is a poor match for mixed-device households, browser-first teams, or users who need mobile capture-to-export tools.

Pros and cons

• Pros: Free plan with no in-app purchases; one-click batches of hundreds of photos; folder drag-and-drop starts processing immediately; separate lossless and lossy modes; resizing across more than 70 formats; overwrite confirmation protects originals; no app data collection is stated by Apple.
• Cons: Mac-only support excludes other platforms; compression claims cover PNG, JPG, and GIF rather than every resizing format; lossy mode trades some visual quality for its larger savings; the paid 29.99 USD edition does not describe extra benefits.

Alternatives

For a wider platform mix, PixelMod runs on macOS, Windows, and the web, with a free tier that allows five web downloads monthly, unlimited desktop downloads, a 0.5 MP maximum, and a standard model; its Starter plan is $7 a month.

XnConvert is a freemium option for Linux, macOS, and Windows, with free private, educational, and nonprofit use and company licensing from 6.50 EUR for 100+ licenses. Converseen is free GNU GPL software for Linux, macOS, and Windows, making it preferable when open-source cross-platform coverage matters.

Batch Resize targets iOS and macOS; its free download contains advertising, while removing ads costs 34.99 USD once. Desqueeze is an iOS alternative with a free Basic plan for photos up to 4,032 x 3,024 pixels. Fotosizer serves Windows, offering a free Standard Edition and a 11.10 USD one-time Personal license for one computer.

Cantaloupe is a free, open-source dynamic image server for self-hosted and web use. FastStone Photo Resizer is free for personal and educational use on Windows.

See the broader Photo Resizing Software collection for more choices.

Verdict

Photo Size Optimizer is a sensible pick for Mac users who want free, no-subscription batch resizing with a clear choice between fidelity and maximum compression. Its folder workflow, broad resizing-format support, and overwrite warning make routine jobs efficient. Look elsewhere if you need Windows, Linux, mobile, or web access, or if compression across every supported format is essential.