Image Resizer

You have a picture that is too big and something that will only accept a smaller one. Drop it below, say what size you want, and take the result.

And if you have hesitated before now about handing a photograph to a website, do not worry, that instinct is a good one and it is the reason this page works the way it does. Your picture never leaves your computer. There is no upload and no server involved at any point, and you can prove that in half a minute. I will show you how further down.

Why not uploading matters more here than anywhere else

Think about what actually goes through an image resizer.

Passport photographs for a visa application. A signed contract somebody photographed. A screenshot of a bank statement for an expenses claim. Pictures of children for a school form. An ID card for a landlord.

Almost every resizer on the first page of results takes that file, sends it to a machine somewhere, resizes it there and sends it back. Most of them say nothing about what happens to the copy that stayed behind.

This one does the work in your browser, which every browser has been able to do for years. There is nowhere for the picture to go.

A side effect worth knowing about

Resizing here also strips the hidden information a camera writes into a photograph. That includes the make and model of the phone, the date and time, and on most phones the exact location where the picture was taken.

Most people have no idea that is in there. If you have ever put a photo of something you were selling online, the coordinates of your house may well have gone with it.

Where it stops. This cuts both ways and you should know which you want. If you were relying on that information, for a photo library that sorts by date or by place, the resized copy will not have it. Keep the original.

Why phone photos come out sideways, and why they do not here

This is a real bug in a surprising number of resizers, and now you will know what you are looking at when it happens.

When you turn your phone sideways to take a picture, the camera usually does not turn the pixels. It records them the same way round every single time and writes a small note into the file saying which way up the picture should be shown.

Think of it like a book on a shelf with the title printed sideways. The book is fine. Anyone can read the spine by tilting their head. But a machine that copies out only the letters, without the note about tilting, produces something that reads sideways for ever.

Copy the image without reading that note and out comes a portrait photograph lying on its side. This page reads it first and turns the picture properly before resizing.

Where it stops. If a photograph was already saved sideways by something else, with no note in it, nothing can know that. It has no way of telling a picture of a horizon from a picture of a wall.

Aiming at a file size instead of a width

Plenty of forms do not care about the width at all. They say the file must be under 100 KB, or under 2 MB, and leave you to work out how.

Switch to the file size mode, type the number, and the tool finds it for you.

There is no formula for this and anybody claiming one is guessing. How small a picture squashes down to depends entirely on what is in it. Take a photograph of a brick wall and a photograph of a clear blue sky, at the same dimensions and the same quality setting. They can differ several times over in file size, because one has detail in every square inch and the other is almost entirely one colour.

So the tool does the only honest thing: it saves the picture, measures it, adjusts, and tries again, narrowing in until it is under your number. Ten goes gets it close.

Where it stops. PNG has no quality dial to turn, so this mode needs JPEG or WebP and the tool says so rather than pretending. And if you ask for something impossible, like a detailed photograph under 5 KB, you will get the smallest it can manage and it will look terrible. No tool can beat that, it is simply how much information the picture contains.

Which format to choose

• JPEG for photographs. It is what nearly everything accepts, and it is very good at pictures of real things.
• PNG for screenshots, logos, diagrams, anything with flat colour or sharp lines, and anything that needs a transparent background. It does not lose quality, which also means the files are big.
• WebP when you are putting it on a website. It typically comes out noticeably smaller than JPEG at the same quality, and every current browser handles it.

The tool warns you when a choice is likely to backfire. Turning a JPEG into a PNG usually makes the file bigger rather than smaller, and it cannot restore quality that has already gone.

Making a picture bigger does not work, and here is why

You can do it. The tool will let you. It will also tell you that it is not an improvement.

A photograph holds a fixed number of dots. Making it bigger does not go back and collect more information about the scene, because that information was never recorded. All it can do is spread the dots it has over a larger area and guess at what belongs in the gaps. The result looks soft, and edges look slightly rubbery.

Sometimes enlarging is the only option you have, and that is fine. Just go in knowing it is a compromise rather than a fix.

Frequently asked questions

How do I check my picture is really not being uploaded?

Two ways, and the second one is conclusive.

Open your browser’s developer tools, go to the Network tab, and drop a picture in. Nothing is sent.

Better still, load this page, turn your internet off completely, and then use it. It carries on working, because everything is happening on your own machine. Nothing that needed a server could do that.

What is the biggest picture it can take?

Anything up to about 8,000 pixels on a side comfortably, which covers every phone and nearly every camera. Bigger than that and it will shrink it to fit, keeping the shape, and tell you it did.

The limit is your browser rather than the page. Browsers refuse to work on a picture past a certain size, and the exact point differs between them, so this stays comfortably under the lowest one.

Can it open a HEIC photo from my iPhone?

Usually not, and it will say so rather than failing silently. Most browsers cannot read that format at all.

The way round it is on your phone. In Settings, Camera, Formats, choose Most Compatible and new photos will be JPEG. For one you already have, sharing or emailing it to yourself usually converts it on the way.

Can it do several pictures at once?

Not yet. One at a time. If that is something you need for a lot of pictures, say so in the comments and I will look at adding it.

Why is my resized picture bigger than the original?

Usually because the format changed. A JPEG saved as a PNG will nearly always grow, sometimes several times over.

The other cause is quality. If the original was saved at a low quality and you are saving at a high one, the file can grow even though the picture got smaller. The tool tells you when the result came out larger, so you can lower the quality or simply keep what you had.

If you have any issues, you can ask me via comment, and I will love to help you out.