Does removing a background reduce the image quality?

Removing it does not, but saving it in the wrong format will. The cutout itself only changes the alpha channel, which records how opaque each pixel is. The colour data underneath is untouched, so a cutout at your photo's own resolution is exactly as sharp as the photo was. The damage happens at the save step: JPG has no alpha channel at all, so a transparent cutout saved as one gets flattened onto white and the transparency is gone for good. Save as PNG or WebP and the quality question does not arise. The other way to lose quality is a tool that hands back a small preview instead of your real resolution, which is a limit of the tool rather than of the technique.

Why do cutouts go wrong on hair, glass and smoke?

Because an automatic tool decides each pixel is subject or background, and those three things are neither. A single hair is thinner than a pixel, so that pixel is a genuine mixture of hair and whatever is behind it. Glass and smoke are see-through across their whole area rather than just at the edge. Getting them right needs a true matte with partial transparency through the middle of the object, which is a harder problem than segmentation and is why professional compositing still involves a person. In practice: hair survives against a clean, plain backdrop and turns to mush against a detailed one, and a wine glass will come back as a glass-shaped silhouette with the old background trapped inside it.

How do I remove a background on an iPhone or Android?

On an iPhone running iOS 16 or later, open the photo, press and hold the subject, and lift it out. A menu appears with Copy and Share, and Share to Files gives you a transparent PNG. It is genuinely good on people and pets and it needs nothing installed. On Android the equivalent depends on the phone: Google Photos has Magic Eraser for removing objects rather than backgrounds, Samsung Galaxy phones have the same press-and-hold lift as the iPhone, and everything else falls back to a browser tool. The iPhone method has one real limit, which is that you cannot adjust anything. You get the cutout Apple decided on, and if the edge is wrong there is no slider.

Can I remove a background in PowerPoint or Google Slides?

PowerPoint yes, Google Slides not really. PowerPoint has had a Remove Background button under Picture Format since 2010, and it works by letting you paint over the regions to keep and discard. It is slow and the edges are coarse, but it is already on the machine and the result stays inside the deck, which for an internal slide is often the whole requirement. Google Slides has no background remover. What it does have is a transparency slider under Format options, which fades the whole image rather than cutting anything out. The usual workaround is to make a transparent PNG elsewhere and insert that, which is why so many searches for this end up on a browser tool.

Is it legal to remove the background from someone else's photo?

Removing a background creates a derivative work, so the copyright question is the same one that applies to any edit: it depends on who owns the photo and what you are doing with it. Your own photos, stock images licensed for modification, and product shots supplied by a brand for resale are all normally fine. Somebody else's photograph pulled off the web is not, and cutting the subject out does not change that. There is a separate issue with photographs of people, where many countries have publicity or personality rights that apply regardless of who owns the copyright in the image. None of this is legal advice, and if the answer matters commercially it is worth twenty minutes of somebody who does give it.

What is the difference between a background remover and an object eraser?

They solve opposite problems and get confused constantly because both are sold as AI photo tools. A background remover keeps one thing and deletes everything around it, leaving transparency behind. An object eraser deletes one thing and invents plausible pixels to fill the hole, so the picture stays rectangular and opaque. Google's Magic Eraser, Photoshop's Generative Fill and Samsung's object eraser are all the second kind. If you want a person on a transparent background for a slide or a shop listing, you want a background remover. If you want the stranger walking through your holiday photo gone, you want an eraser, and no background remover will do it.

How to remove the background from an image

Six ways to do it, what each one costs you in quality, money or privacy, and the one distinction that decides which to reach for.

Free toolBackground RemoverCut the background off a photo in your own tab, at full resolution. The model runs here, so the picture is never uploaded.Open the remover

The short answer

Ask what is behind the subject before you pick a tool. That one question splits the job in two, and picking the wrong side is why so many cutouts come out badly.

A busy or detailed background: you need a model that understands what a subject is. Any AI background remover, including the one on this site.
A flat white or grey backdrop: you do not need a model at all. Erasing that one colour is faster and more exact than any AI, and it is what a studio shot, a scanned logo or a diagram wants.
You are on an iPhone: press and hold the subject in the Photos app. It is free, instant and already there.
The picture must not leave your machine: use a tool that runs the model in your browser rather than on a server. Most do not.

The six methods, side by side

Method	Quality	Cost	Where your photo goes
Browser AI tool, in-page	Good on people and objects	Free, full resolution	Nowhere. The model is downloaded to you
Browser AI tool, server	Often the best available	Free preview, paid full size	Uploaded to their servers
iPhone press and hold	Very good on people and pets	Free	Stays on the phone
Photoshop	The best, with work	Subscription	Stays on the machine
macOS Preview	Good on a clear subject	Free, already installed	Stays on the Mac
PowerPoint	Coarse edges	Free with Office	Stays in the deck

1. In a browser, without uploading

A segmentation model is a file of numbers, and a browser can download a file and run it. That is the whole trick behind an in-page background remover: the model comes to your picture rather than your picture going to the model. You pay a one-off download for the weights, tens of megabytes, and after that every cutout is arithmetic happening in the tab.

The trade is real and worth stating. The models small enough to download are not quite the models a well-funded company runs on a GPU, so on a genuinely hard picture, fine hair against foliage, a paid server tool may still beat it. What you get in exchange is your actual resolution for free, no account, and a photo that never leaves the machine. For a headshot, a passport photo, a picture of a child or a client's file under NDA, that last point tends to end the discussion.

Worth knowing when you compare: several sites advertise "on-device" processing without doing it. The test takes ten seconds. Open the network panel, run a cutout, and look for a large model download. If the page transferred under a megabyte in total and still produced a perfect cutout, the work happened somewhere else.

2. How to remove a white background: do not use AI at all

This is the most common mistake on this whole topic. A product on seamless white, a scanned logo, a signature or a chart has no subject in the sense a model is looking for, so the model guesses, and its guess has soft edges in places where the truth is a hard boundary. Erasing the colour is not the cheap version of the AI here. It is the correct answer.

The one thing to check in whatever tool you use is whether it floods inward from the edge of the image or matches every pixel in the picture. Matching every pixel punches holes through the white of a shirt, a tooth, a highlight and the inside of a letter O. Flooding from the border removes only white that is connected to the outside, which leaves all of those alone. A tool that offers a "contiguous" or "connected" option is doing the second thing.

3. On an iPhone, with nothing installed

Since iOS 16, opening a photo and pressing and holding on the subject lifts it out with a shimmer, and the menu that appears offers Copy and Share. Share to Files gives you a transparent PNG you can use anywhere. It is remarkably good on people and animals and it is the fastest route on this whole page.

Its limit is that there are no controls. You get Apple's decision about where the edge is, and if it clipped an ear or left a halo there is nothing to adjust. It also only knows about a handful of subject types, so a product shot often does nothing at all when you hold on it.

4. Photoshop, when the result has to be perfect

Select Subject followed by a Layer Mask gets you to the same place an automatic tool does, in about the same time. What Photoshop has that nothing else here does is Select and Mask, and specifically the Refine Edge brush, which is the only tool in this list that genuinely recovers hair against a complicated background. If the picture is going into an advert, this is still the answer.

It is a subscription, and the automatic selection on its own is no better than the free options. The value is entirely in what you can do afterwards.

5. macOS Preview, which is already on the Mac

Open the image in Preview, click the markup toolbar, and there is an Instant Alpha tool that erases by colour, plus a Remove Background button in recent versions that does a subject cutout. Both are free, both stay on the machine, and Instant Alpha in particular is a good answer for a flat backdrop. Export as PNG to keep the transparency.

6. PowerPoint, when it never has to leave the deck

Picture Format, then Remove Background. PowerPoint makes a guess and shades what it plans to delete in magenta, and you paint with Mark Areas to Keep and Mark Areas to Remove until it is right. The edges are coarse and you would not use it for anything printed. For a slide going up on a projector in twenty minutes it is entirely adequate, and the file never leaves Office.

Google Slides has no equivalent. Its transparency slider fades the whole picture rather than cutting anything out, so the workaround is to make a transparent PNG elsewhere and insert that.

Save it as PNG, or you will lose the transparency

Whichever method you use, the last step is where cutouts get thrown away. Transparency lives in an alpha channel, and only some formats have one.

PNG keeps it, is lossless, and is read correctly by everything. Use this unless you have a reason not to.
WebP keeps it too and is usually about a third of the size, which makes it the better choice for a web page. Safari cannot create one.
JPG has no alpha channel at all. A transparent cutout saved as a JPG is flattened onto white, and there is no undo.
SVG is not an option here. A photograph is pixels, and putting pixels inside an SVG wrapper does not make it a vector.

If you end up with a cutout in the wrong format, the image converter will move it across without another upload.

A checklist for a cutout that looks right

Look at it on a dark background, not a white one. A pale halo is invisible against white and obvious against black, and white is what every preview shows you by default.
Check the gaps. Between an arm and a body, through the handle of a mug, between the legs of a chair. Automatic tools miss enclosed holes constantly.
Zoom to the hair, if there is any. That is where the difference between a good tool and a bad one actually lives.
Pull the edge in a notch if there is a fringe. The outer ring of pixels carries the old background's colour, and removing it costs almost nothing.
Confirm the saved file, not the preview. Open it over something coloured. This is the step that catches a JPG that flattened onto white.