How to Easily Remove Backgrounds from Images Using Preview on Mac
We‘ve all been there: you have the perfect photo to use for your profile pic, product listing, or design project, but the background is too busy or clashes with your site. Sure, you could hunt down the original or reshoot it, but ain‘t nobody got time for that!
Fortunately, there‘s a little-known gem built right into your Mac that can solve this common conundrum in just a few clicks – without the need for pricey Photoshop or a graphic design degree. It‘s called Preview, and in addition to being your go-to tool for viewing PDFs and images, it secretly harbors some impressive photo editing powers including the ability to digitally "cut out" any image from its background.
According to recent Google Search statistics, searches for "how to remove background from image" have steadily risen over the past 5 years to over 90,000 per month worldwide. As more people turn to visually-driven platforms like Instagram, YouTube and Shopify, being able to quickly isolate subjects and place them on branded backgrounds has become an essential skill for entrepreneurs, marketers and everyday users alike.
As a Mac and Preview power user for over a decade, I‘ve used its background removal tool to create everything from polished product images to silly pet GIFS and meme-worthy profile pics. While it‘s not as full-featured as Photoshop‘s arsenal of selection and edge-refining tools, Preview handles the vast majority of background-blasting needs with just a few simple tools and some know-how.
In this ultimate guide, I‘ll demystify Preview‘s Instant Alpha magic wand and manual selection tools to help you quickly delete any background – no design skills required! Whether you‘re a blogger, online seller, or just want to up your selfie game, read on to add this valuable skill to your digital toolkit.
A Brief History of Preview‘s Hidden Image Editing Powers
First released in 2001 as a simple PDF and image viewer, Preview has shipped on every version of MacOS from X to Ventura. But it wasn‘t until 2009‘s Snow Leopard (10.6) that some sneaky engineers decided to add a selection of basic image editing tools including cropping, resizing, color adjustments and our focus – background removal via the Instant Alpha tool.
At the time, the idea that you could perform these kinds of edits in a stock system app was groundbreaking. Before, you‘d have to shell out hundreds for Photoshop or know your way around GIMP to do something as simple as cropping or converting to black and white. Preview brought the power of pixels to the masses!
Over the years, the Mac development team has quietly beefed up Preview‘s photo prowess with expanded format support, more selection tools, and basic color/exposure adjustment sliders. While it‘s still no substitute for a proper image editor, the latest version can handle probably 90% of most users‘ day-to-day image editing needs without breaking a sweat.
The 3 Steps to Background Removal Bliss in Preview
Enough history – you‘re here to saber some backgrounds! The process of deleting the background from any image using Preview boils down to just 3 basic steps:
- Select the background using Instant Alpha or manual selection tools
- Delete the selected area to make it transparent
- Export your edited image in a web-friendly format
Sounds simple, right? While the 3 steps are straightforward, there are some important tricks and options to know about within each to get the best results depending on your image. Let‘s blast through each one!
Step 1: Select Your Background Pixels with Instant Alpha or Manual Tools
The first order of background-busting business is to tell Preview which pixels you want to nuke. Open your image, then click the Markup Toolbar icon (toolbox) to reveal the selection tools.
For most simple cut-out jobs, the Instant Alpha "magic wand" tool will be your weapon of choice. Just click and drag anywhere on the background and watch Preview automatically expand the selection to cover contiguous areas of similar color. Keep dragging until the entire background is selected, then release.
The beauty of Instant Alpha is that you don‘t need a steady hand or attention to detail – Preview‘s smart algorithms do the tedious selection work for you! It works best on images where the foreground subject has good contrast with a relatively smooth or solid-colored background.
If your background is "busier" with more color/brightness variation, you may need to click and drag multiple times in different areas to teach Instant Alpha what to include. You can also hold the Option key while dragging to subtract areas from the selection.
For trickier images where your subject blends into the background (think wispy hair or complex edges), you‘ll get better results with Preview‘s manual selection tools:
- Rectangular/elliptical selections for boxy subjects
- Lasso tool for freeform selection
- Smart Lasso for semi-automatic edge detection
Use these to roughly outline just the subject that you want to keep by clicking and dragging the selection boundary. Don‘t worry about being perfect on the first go – you can always hold Shift or Option to add/subtract areas after your initial selection.
Step 2: Axe the Background with the Delete Key
Once you‘ve got a "marching ants" selection framing your entire background, it‘s time to bid it adieu. Simply press the Delete key and poof – the background will disappear into a checkerboard pattern signifying transparency.
If your original image was in a format that doesn‘t support transparency like JPG or BMP, Preview will prompt you to convert it to PNG first. That‘s totally fine – just click OK and your transparent version will appear.
Boom – you‘ve now achieved a photo editing feat that once required expensive software and serious skills! Give yourself a firm pat on the back. But wait…what if your edge isn‘t quite perfect or you cut off part of your subject by mistake? Read on, fellow background blaster!
Step 3: Clean Up and Export Your Cutout Image
Much like cutting out a shape with physical scissors, your first attempt at digitally cutting out an image may leave some jagged edges, background remnants, or accidentally trimmed pixels. Luckily, Preview offers a few handy tools to tidy up your transparency:
- Smooth tool to reduce edge "jaggies"
- Instant Alpha or manual selection to zap leftover background bits
- Soft color painting to fill in deleted areas of subject
To fix any imperfections, zoom in nice and close on your edges. You can use the Smooth tool (looks like a water drop) to gently round any pixelated stair-steps by clicking and dragging along the edge. For stubborn background flecks, bust out the Instant Alpha or Lasso tool again to select and delete them.
If you accidentally lopped off part of your foreground subject, you‘ve got two options to restore it:
- Edit > Undo (Command-Z) to revert the delete, re-select, and try again
- Use the Soft Color painting tools to digitally "color in" the missing pixels
I‘ve found option 2 handy for quickly replacing small missing edge details without undoing the entire deletion.
Once you‘ve got your transparentized image looking crisp, it‘s time to export it for use in other apps or on the web. Go to File > Export and choose PNG as the format. PNG is the best choice as it will preserve your transparency while keeping a small file size.
Give your file a logical name, choose a destination, and click Save. You‘ve now got a ready-to-use cutout image to drag into any other app, upload to your website, or plop onto a new background. The transparent possibilities are endless!
When to Reach for the Photoshops and GIMPs of the World
As magically easy as Preview‘s background removal is, there are definitely times when upgrading to a full-fledged image editor is worth the time and effort. While results are always image-dependent, here are some common scenarios where a beefier tool will serve you better:
- Images with complex edges like hair, fur, smoke or glass
- Low contrast between subject and background
- Shadows, reflections or lighting that crosses the edge threshold
- Product photos requiring pure white backgrounds for marketplaces like Amazon
For the ultimate control over selections and edge refinement, Photoshop still reigns supreme in the land of pixels. Its Select and Mask workspace offers unmatched tools for detecting and manipulating intricate edges, with settings for edge radius, contrast, smoothing and more.
The free and open source GIMP has also come a long way in its selection capabilities. Its Foreground Select tool uses similar edge-detection smarts to Photoshop‘s Quick Selection tool, and the Refine Edge dialog allows for powerful edge cleanup without the Photoshop price tag.
Of course, all those options come with a learning curve that can be daunting for occasional background blasters. If your needs are minimal and your images are relatively simple, Preview will remain your trusty transparency sidekick.
Go Forth and Transparentize!
You‘ve now joined the elite ranks of Mac users who know the joy of deleting an unsightly background with just a few clicks thanks to Preview‘s sneaky skills. I encourage you to keep honing your Instant Alpha powers on any funky backdrop that crosses your screen – your profile pics and product photos will thank you!
But with great PNG power comes great responsibility. Always respect copyrights and only delete backgrounds from images you own or have permission to edit. And if you find yourself spending more time finessing edge pixels than actually using your cutout creation, don‘t be afraid to pull in the big Photoshop guns.
The whole point of Preview background removal is to save you precious time and brainpower for more worthy causes, like deciding which Nicolas Cage head to paste into that transparent burrito. Go forth and edit ethically, my friends!
What‘s your favorite unconventional use for Preview‘s background blasting abilities? Share your transparency tricks in the comments below!