Resize a whole batch by long edge, width × height, percentage or a social-media preset, keeping the aspect ratio if you like.
Your images are processed on your own device and are never sent to a server.
Drag and drop your images
or click to choose · Ctrl+V to paste (up to 30, 50MB each)
Everything runs in your browser. Your images are never sent to a server.
MamePress changes the pixel dimensions of your images, one at a time or a whole batch with the same settings. What sets it apart is where that happens: the whole job runs inside your browser. Nothing is uploaded to a server, so a private photo or a confidential document stays on your device. There is no account to create, nothing to pay, and no watermark on the result.
Every mode keeps the aspect ratio unless you tell it not to, and none of them crops. In Width × height, while the button reads Aspect ratio locked, the two numbers are a box rather than an exact size: the image is scaled to the largest size that fits inside it, so a photo that is not 3:1 does not come out at 1500×500 even if you type 1500×500. To get exactly the numbers you typed, switch the button to Aspect ratio free — the image is then stretched or squashed to fit, which is the one case where the proportions change.
Presets work the same way. They shrink the image until it fits inside the preset and leave the ratio alone, so a 4:3 photo run through a 1080×1080 preset comes out at 1080×810, not as a square. If you need the exact shape as well, crop the image to that ratio first and resize it afterwards.
To enlarge a small image, choose Width × height and enter numbers larger than the original. With the aspect ratio locked you only need one of them: an 800×600 image with 1600 as the width and the height left empty comes out at 1600×1200. Long edge and Preset are "fit inside" modes and never go above the original size, and Percentage stops at 100%, so if the tool seems unable to enlarge, it is the mode.
Enlarging has a limit. It fills in the pixels between the ones that exist by calculation, and it cannot bring back detail that was never in the picture, so the further an image is stretched the softer its edges get. This tool does plain interpolation; it does not do AI upscaling. Up to about twice the original size is usually usable. Beyond that, start from a larger original if you can. For print, work out the pixel count you need from the print size and type it straight into Width × height.
"Size" means three things for an image. The pixel dimensions (1920×1080) are what this tool changes. The file size (350KB, 2MB) usually falls when the dimensions do, but a resizer does not aim at it: if an upload form asks for a file under 200KB, that is a job for the image compressor, which takes a target size and compresses to fit under it. DPI is a note in the file about how large to print it. Recording 300dpi here changes that note in a JPEG and nothing else — the pixels, and therefore the sharpness, stay exactly as they were.
Are my images uploaded anywhere?
No. The resizing is done inside your browser, on your own device, and the images never leave it. There is no upload endpoint to send them to, which is why there is also no queue, no waiting for a server and nothing to delete afterwards.
Can I resize an image without cropping or stretching it?
Yes, and that is what happens unless you ask for something else. Long edge, Percentage and Preset always keep the aspect ratio. Width × height keeps it too while the button beside the two boxes reads "Aspect ratio locked": the two numbers are treated as a box and the image is scaled to the largest size that fits inside it. Nothing is ever cropped. The only way to stretch or squash an image is to switch that button to "Aspect ratio free", which writes exactly the width and height you typed.
Can I make an image larger?
Yes, in Width × height. Enter numbers larger than the original and the image is enlarged; for example, an 800×600 image with 1600 as the width and the height left empty comes out at 1600×1200. The other three modes only shrink: Long edge and Preset leave an image alone if it is already smaller than the target, and the Percentage box stops at 100%. Enlarging here is plain interpolation, not AI upscaling, so the more an image is stretched the softer it looks.
Does resizing lose quality?
Shrinking throws away pixels you no longer want, and the result usually looks as sharp as the original at its new size. JPEG and WebP output is written at quality 0.92, which favours the look over the file size; PNG output is lossless. Enlarging is different: no tool can add detail that was never in the picture, so an enlarged image gets softer. Up to about twice the original size is usually fine.
How many images can I resize at once?
The list holds up to 30 images at a time, and that cap is on the whole list, not on a single drop. They are all resized with the same settings and can be downloaded one by one or together as a ZIP. Download what you have, press Clear, and continue with the next 30, so there is no limit on the total. Each file can be up to 50MB.
Which formats does it read and write?
It reads JPEG, PNG, WebP, AVIF, GIF, BMP, HEIC and HEIF, and writes JPEG, PNG or WebP. With Output format left at "Same as input", a JPEG, PNG or WebP keeps its format; HEIC and HEIF come out as JPEG, and AVIF, GIF and BMP come out as PNG, because a browser cannot write those formats. The card says so when the format changed. An animated GIF is read as its first frame; the animation is not kept. JPEG has no transparency, so transparent areas become white when the output is JPEG.
I need the file under 200KB or 2MB. Is this the right tool?
Not quite. This tool changes the pixel dimensions. The file usually gets smaller as a result, but it does not aim at a number of kilobytes. To get a file under a set size, use the image compressor on this site: its Target size mode takes a ceiling in KB and compresses to fit under it. If the picture is far larger than it needs to be, resize it here first and compress the result.
What does Record DPI do?
It writes a print resolution, such as 300dpi, into the file. It is recorded only in JPEG output, not in PNG or WebP. The pixel count does not change, so the image does not get any sharper; the value only tells a printer or a layout program how large to print it. Left at "Don't record", the exported file states no print resolution at all.
Can I resize iPhone photos (HEIC)?
Yes. HEIC and HEIF files are decoded in the browser, so a photo straight off an iPhone can be dropped in without converting it first, and it comes out as a JPEG unless you choose PNG or WebP. There is no app to install.
Is there a maximum output size?
Only the one browsers themselves have. One side can be at most 65535px, and the total area can be no more than that of a 16384×16384px image. A size above either limit is refused with a message that says which limit was hit.
Need the file under a set size in KB or MB? Use theimage compressor. To cut the background out of a picture, there is thebackground remover. Both run in the browser too.
