Best Image Resizer for Mac: 9 Tools for Batch Resizing (2026)

By Hieu Dinh

Best Image Resizer for Mac: 9 Tools for Batch Resizing (2026)

The right image resizer for Mac depends entirely on how often you resize and how many images you handle. For a single Slack avatar, Preview gets you there in 30 seconds. For 500 product photos that need to land at 1200px wide before a client deadline, Preview is a productivity disaster. This guide walks through every viable Mac image resizing tool in 2026, from built-in freebies to dedicated batch apps, so you can pick the one that actually fits your workflow.

Built-in Image Resizing on Mac

macOS has more native resizing capabilities than most people realize.

1. Preview (Free, Built-in)

The default image viewer is also a competent single-image resizer.

How to resize an image in Preview:

  1. Open the image in Preview.
  2. Click Tools → Adjust Size.
  3. Change units to "pixels."
  4. Type your target width or height. The other dimension auto-fills.
  5. Click OK and File → Save (or File → Export to change format).

Preview handles JPG, PNG, HEIC, TIFF, GIF, and PDF. Quality is fine for casual use — bilinear-style interpolation.

  • Best for: Single images, occasional use
  • Limit: No batch mode in the UI (though you can select multiple files and resize them all to the same dimensions)

For the technical details on what's happening behind the scenes, see our resize image pixels guide.

2. Automator (Free, Built-in)

macOS Automator can build reusable image-resize workflows.

Build a "Resize to 1200px" droplet:

  1. Open Automator → New → Application.
  2. Drag in the action Scale Images.
  3. Set width to your target (e.g., 1200 pixels).
  4. Save as "Resize 1200" on your Desktop.
  5. Drag any folder of images onto it — done.
  • Best for: Repeat workflows on the same dimensions
  • Limit: One dimension per droplet; no quality control

3. Shortcuts App (Free, Built-in)

The modern successor to Automator. Build resize workflows that can run via Spotlight, the menu bar, or from any app's share sheet. Useful if you want resizing accessible from anywhere on the system.

  • Best for: Quick-access workflows

Best Paid / Power Image Resizers for Mac

4. Compresto

Compresto is a native macOS image resizer built around batch operations. Drop a folder of images, choose a max width or height in pixels, and the app resizes everything in seconds using high-quality interpolation. Combines resize with compression and format conversion in the same pass, so you don't need to chain multiple apps.

  • Best for: Mac creators handling lots of images
  • Strength: Hardware-accelerated; batch of 500 images runs in under a minute on Apple Silicon
  • Pricing: Free tier; one-time pro license

5. PhotoBulk

A long-standing favorite for batch image work on Mac. Drop photos, pick a preset (resize, watermark, convert, optimize), click Start. Simple, fast, and stable.

  • Best for: Streamlined batch resize + watermark
  • Pricing: Paid (~$10 one-time)

6. Resize Sense

A Mac-exclusive resizer aimed at professionals. Flexible resizing and cropping options, exact pixel/percentage/fit-mode controls, and aspect ratio handling that doesn't distort.

  • Best for: Photographers needing precise crops + resize
  • Pricing: Paid (~$20)

7. BatchPhoto

Powerful three-step batch processor: load images, apply filters/resize/format change, choose destination. Handles hundreds of images at once across JPG, PNG, TIFF, RAW, and more.

  • Best for: Photographers with mixed-format libraries
  • Pricing: Paid (~$40 one-time)

8. iResize

A simpler, drag-and-drop batch resizer for Mac. Drop images on the app window, set the target size, get optimized output. Less feature-rich than the others but very fast.

  • Best for: No-frills batch resizing
  • Pricing: Paid (~$5)

9. Pixelmator Pro

A full image editor with strong batch automation. Use the built-in Automator action "Batch Process" to chain resize, crop, color, and export operations. Overkill for resize alone, perfect if you're already editing photos here.

  • Best for: Editors who already use Pixelmator
  • Pricing: Paid (~$50 one-time)

How to Batch Resize Images on Mac (Step by Step)

Option 1: Preview (Free, Limited)

  1. Select all images in Finder.
  2. Right-click → Open With → Preview.
  3. In Preview's sidebar, Edit → Select All (Cmd+A).
  4. Tools → Adjust Size → set dimensions → OK.
  5. File → Save All.

Works for small batches (20–50 images). Slows down dramatically beyond that.

Option 2: Automator (Free, Repeatable)

  1. Build a "Scale Images" droplet (see step #2 above).
  2. Drag folders onto the droplet whenever you need to resize.

Works at any batch size but locks you to a single dimension per droplet.

Option 3: Compresto (Fastest, Most Flexible)

  1. Open Compresto.
  2. Drop your image folder onto the app.
  3. Set target max width/height in pixels.
  4. (Optional) Set compression quality and output format.
  5. Click Compress — batch runs with hardware acceleration.

Works for batches of thousands without slowdown. See our batch image compression tools guide for more options.

Image Resizer for Mac: Quick Decision Guide

  • Resizing 1–5 images, no installation? Preview.
  • Resizing 5–50 images, same dimensions every time? Automator droplet.
  • Resizing hundreds of images regularly? Compresto or PhotoBulk.
  • Photographer working with RAW + JPG mixed batches? BatchPhoto.
  • Already in Pixelmator Pro? Use its batch processing.
  • Need precise per-image crop control? Resize Sense.

Common Mac Image Resize Use Cases

Resize for Web

Target: 1200–1920px wide for hero images, 800px for body images. Use Compresto or Preview, output as WebP for ~30% smaller files than JPG. See our image optimizer guide for the compression side.

Resize for Email

Target: 1024–1280px wide, JPG at 75% quality. Keeps attachment under 1 MB while staying readable. See reduce file size for email attachments.

Resize for Social Media

Each platform has different dimensions. Common targets:

  • Instagram Feed: 1080 × 1080 or 1080 × 1350
  • Twitter: 1600 × 900
  • LinkedIn: 1200 × 628
  • Facebook: 1200 × 630

For Instagram video specifically, see resize video for Instagram.

Resize for Print

Target: 300 DPI at physical size. For a 4×6 inch print, that's 1200 × 1800 px. Don't downscale below your print target — you can't recover detail. See 300 DPI resolution explained.

Resize to Specific KB Size

Sometimes the spec is by file size, not pixels (passport photos, government forms, online applications). Use a tool that targets KB rather than dimensions:

Or use our JPG size reducer guide for the broader approach.

What to Look for in a Mac Image Resizer

Beyond price, four features distinguish good resizers from mediocre ones:

  1. High-quality interpolation — Bicubic Sharper for downscaling, AI upscaling for enlargement. Preview uses basic interpolation; pro tools use better algorithms.
  2. Batch processing — Drag a folder, not files. Must handle 1000+ images without slowing down.
  3. Resize + compress in one pass — Two-step pipelines (resize, then compress) cost time and quality. Tools like Compresto bundle both.
  4. Aspect ratio handling — Lock aspect ratio when shrinking, offer crop/pad options when changing aspect.
  5. Format conversion — Resize from HEIC and output as JPG/WebP in one step. Especially useful for HEIC photos from iPhone.

Frequently Asked Questions

What's the best free image resizer for Mac?

Preview for one-off jobs, Automator for repeat workflows. Both are built into macOS and work without any installation.

Can I batch resize images on Mac without third-party apps?

Yes. Select images → Open in Preview → Cmd+A → Tools → Adjust Size. Or build an Automator "Scale Images" droplet for repeat use.

How do I resize an image without losing quality on Mac?

Use a tool with high-quality interpolation (Compresto, Photoshop, Pixelmator Pro). Downscaling is effectively lossless to the eye when done with Bicubic Sharper or equivalent. Avoid repeatedly resizing the same file.

Is there an image resizer for Mac that handles HEIC?

Yes — Preview, Compresto, and Pixelmator Pro all handle HEIC natively. For HEIC-to-JPG conversion specifically, see our HEIC to JPG converter guide.

What's the fastest image resizer for Mac?

Hardware-accelerated tools on Apple Silicon. Compresto uses Metal acceleration; PhotoBulk and BatchPhoto are also fast on M-series chips. Preview is slow on large batches.

Can I resize images and compress at the same time?

Yes, with Compresto, PhotoBulk, BatchPhoto, and Pixelmator Pro. One pass is faster and produces smaller, higher-quality files than resizing first then compressing separately.

A Faster Image Resizer for Mac

If you regularly resize more than 20 images at a time, dedicated batch tools will save you hours. Try Compresto — drop a folder, set a max width, get web-ready images in seconds. Pairs resize with compression and format conversion in one pass, runs entirely on your Mac, and handles batches of thousands without slowdown.

For the full image workflow, see our image optimizer guide, bulk image compressor guide, and JPG size reducer guide.

Ready to compress your files? Join thousands of creators using Compresto ⚡