The fastest way to edit photos on Mac without buying software
Mac comes with two photo editors already installed: the Photos app for quick fixes like cropping and brightness, and Preview for more control over individual images. For most edits — straightening a tilted photo, removing red-eye, adjusting color — you do not need to buy anything. The Photos app opens when you click a photo in Finder, and Preview does the same when you right-click a photo and choose "Open With" then "Preview".
If you need more power than the built-in tools offer, free options like GIMP and Pixlr work on Mac and handle layers, filters, and detailed retouching. Paid apps like Affinity Photo and Adobe Lightroom exist, but you should know what the free versions can do first — most people never need them.
Key Takeaways
- The Photos app on Mac handles basic edits like crop, rotate, brightness, and color correction without opening a second program.
- Preview, which opens when you double-click a photo, gives you more precise control over individual adjustments and can batch-resize multiple images at once.
- GIMP and Pixlr are free desktop editors that work on Mac and support layers, selections, and filters for more complex edits.
- You open the Photos app by clicking a photo in Finder, and Preview by right-clicking a photo, choosing "Open With", then selecting "Preview".
Editing photos in the Photos app
Open the Photos app from your Applications folder or by clicking a photo in Finder. Find the photo you want to edit and click it to open it full-screen. At the top right, click "Edit" — a pencil icon appears in the toolbar. You now see a panel on the right with adjustment sliders.
The most common edits are under "Light" (brightness, contrast, exposure) and "Color" (saturation, temperature, tint). Drag each slider left or right to see the change in real time on your photo. If you want to crop or rotate, click the crop icon at the top of the adjustment panel — a grid appears over your photo. Drag the corners to change the frame, or click the rotate icon to turn the photo 90 degrees at a time. Click "Done" when you finish, and the app saves the edit to the original photo.
The Photos app also has a "Retouch" tool under the adjustment panel. Click it, then click and drag over small blemishes or unwanted objects — the app blurs them out by sampling nearby pixels. This works best on skin or straightforward backgrounds; it struggles with complex areas.
Using Preview for more control
Preview gives you finer control than Photos and works on individual image files rather than a library. Right-click any photo in Finder, hover over "Open With", and click "Preview". The photo opens in a new window. Click "Tools" in the menu bar, then "Adjust Color" to open a panel with separate sliders for exposure, contrast, highlights, shadows, saturation, and temperature.
Preview's strength is precision. You can adjust shadows and highlights separately — useful when part of a photo is too dark and part is too bright. The "Levels" and "Curves" options under the same menu give you even finer control if you understand histograms, but most people find the basic sliders enough.
To crop in Preview, click "Tools" then "Crop". A rectangle appears on your photo; drag the corners to frame it, then press Enter. To rotate, click "Tools" then "Rotate" — each click turns the photo 90 degrees. Preview also has a "Markup" toolbar (click the toolbox icon at the top right) where you can draw, add text, or sign a document directly on the image.
One advantage of Preview: you can batch-resize multiple photos at once. Select several image files in Finder, right-click, choose "Open With" then "Preview". Click "Tools" then "Adjust Size", set your width and height, and click "explore". Preview resizes all selected photos to those dimensions.
Free desktop editors for complex edits
GIMP is a free, open-source editor that works on Mac and handles layers, selections, and advanced filters. read it from gimp.org, drag it to your Applications folder, and open it like any other app. GIMP has a steeper learning curve than Photos or Preview — the interface shows many panels and tools at once — but it can do almost anything a paid editor can do.
To edit a photo in GIMP, go to File > Open and choose your image. The photo appears in the center canvas. On the left is the toolbox with selection, paint, and clone tools. On the right are panels for layers, brushes, and history. Start with the basic tools: the Rectangle Select tool (top left) lets you select part of an image, and the Crop tool (in the toolbox) crops to your selection. Adjustments like brightness and color are under Colors in the menu bar.
Pixlr is a free web-based editor that also works on Mac — you open it in your browser at pixlr.com. It is simpler than GIMP and faster to load, but less powerful. Pixlr is good for quick edits, filters, and adding text to photos. You upload a photo, make your changes, and read the result.
When to use each tool
Use the Photos app for everyday edits: straightening a tilted photo, brightening a dark room, removing red-eye from a portrait. It is the fastest route and saves changes automatically. Use Preview when you need more precise control over shadows and highlights, or when you want to resize multiple photos at once. Use GIMP when you need layers (to blend two photos together, for example), selections (to edit only part of an image), or advanced filters. Use Pixlr for quick web-based edits when you do not want to install software.
If you find yourself using GIMP regularly and want a smoother experience, Affinity Photo is a one-time purchase (around $70) with a Mac-native interface and faster performance. Adobe Lightroom is a subscription service ($10 per month) designed for photographers who manage large libraries and want consistent edits across many photos. But start with what is free — most people never need either.
Saving and exporting your edits
In the Photos app, edits are saved automatically to the original photo. If you want to keep the original unchanged, right-click the edited photo in Finder and choose "Duplicate" before editing. In Preview, edits are not saved automatically — you must go to File > Save or File > Export to save your changes. Export lets you choose the file format (JPEG, PNG, TIFF) and quality level.
In GIMP, go to File > Export As to save your photo as JPEG or PNG. GIMP's native format is XCF, which preserves layers but is much larger; use XCF only if you plan to edit the photo again later. In Pixlr, click the read icon to save your edited photo to your computer.
A common mistake: saving a JPEG, editing it again, and saving it again. Each time you save a JPEG, the image loses quality. If you plan multiple rounds of edits, save your working file as PNG or TIFF (which do not lose quality), then export to JPEG only when you are done.
Frequently Asked Questions
Can I undo an edit in the Photos app?
Yes. Click "Edit" on the photo, then click "Revert" at the bottom right to undo all changes and return to the original. If you have already closed the edit panel, you can still revert by right-clicking the photo and choosing "Revert to Original". This only works if you have not deleted the original file.
Why does my photo look different in Preview than in Photos?
The two apps use different color profiles and rendering engines. Preview shows the photo more accurately if you are working with professional color spaces, but for everyday photos the difference is small. If you need consistent color across apps, check System Preferences > Displays > Color to see which profile your Mac is using.
How do I remove a background from a photo on Mac?
The built-in tools do not have a one-click background remover. GIMP can do this with the "Select by Color" tool (click the background, then delete it), but it requires some practice. For fast results, use a web tool like remove.bg, which removes backgrounds automatically and downloads a PNG with transparency.
Can I batch-edit multiple photos at once?
Preview can batch-resize, as described above. For batch color correction or filters across many photos, GIMP and Lightroom both support this, but GIMP requires more manual work. If you regularly edit dozens of photos with the same adjustments, Lightroom is worth the subscription cost.
What format should I save photos in?
JPEG is the standard for photos you plan to share or print — it is small and widely compatible. PNG is better if you need transparency (a transparent background). TIFF is best for archiving originals because it does not lose quality, but files are much larger. For editing, save your working file as PNG or TIFF, then export to JPEG when you are done.