How do I resize many images at once?

Drop all your images onto the tool, choose a max width and height or a scale percentage, then click the resize button. Every image is processed in your browser and packaged into a single ZIP file you download in one click — no need to resize them one at a time.

Are my images uploaded to a server?

No. The resizing happens entirely inside your browser using the HTML canvas. Your photos never leave your device, which means there is no upload wait, no file-size limit imposed by a server, and nothing is stored or logged anywhere.

What is the difference between fit, stretch and percentage modes?

Fit scales each image down so it fits inside your width-by-height box while keeping its original aspect ratio, so nothing is distorted. Stretch forces every image to the exact dimensions you type, which can squash or stretch them. Percentage scales each image to a fraction of its own size, so a 50% setting halves both dimensions of every photo regardless of how big it started.

Which output format should I choose?

JPEG gives the smallest files and is ideal for photos and web pages. PNG is lossless and preserves transparency, best for logos, screenshots and graphics. WebP is a modern format that often beats both on size at the same quality. Choose Keep original format to leave each image in its source type where the browser can re-encode it.

Can the tool make images larger as well as smaller?

Yes. In percentage mode any value above 100% enlarges every image. In fit mode, tick the Allow upscaling box so images smaller than your target box are scaled up to fill it. Bear in mind that enlarging a photo cannot add detail it never had, so heavily upscaled images can look soft.

Is there a limit on how many images I can resize?

There is no hard limit set by the tool — it processes whatever you drop. Because everything runs locally, the practical ceiling is your device memory. A few hundred ordinary photos is comfortable on most laptops; for thousands of very large images, work in batches so the browser tab does not run out of memory.

Batch Image Resizer — Gera Tools

A batch image resizer that takes a whole folder of photos and resizes every one of them to the size you want, then hands you a single ZIP file to download. It is built for the moment you have twenty product shots, fifty event photos or a pile of screenshots that all need to be the same width before they go on a website, into an email, or up to a marketplace listing. Instead of opening each image in an editor and exporting it by hand, you drop them all in, set the rules once, and let the browser do the repetitive work.

Everything runs 100% inside your browser. The images are decoded and re-drawn onto an HTML canvas at the new dimensions, re-encoded in your chosen format, and bundled with an in-browser ZIP library. Nothing is uploaded, nothing is stored, and there is no account to create. That makes it fast — there is no upload or download round-trip — and private, which matters when the images are client work, ID documents, or anything you would rather not post to an unknown server.

How it works

You start by dropping your images onto the dropzone or clicking to pick them. Each file is decoded so the tool can read its real pixel dimensions, and a thumbnail grid appears showing the original size next to the target size it will become. Then you pick one of three resize modes. Fit scales each image down so it sits inside a width-by-height box while keeping its aspect ratio, so a tall portrait and a wide landscape both end up bounded by the same limits without distortion. Stretch forces every image to exact dimensions. Percentage scales each image relative to its own size, which is the right choice when the originals vary a lot and you just want everything half as big.

Next you choose the output format — JPEG for the smallest files, PNG for lossless transparency, WebP for modern compression, or keep each image in its original format. A quality slider controls how aggressively JPEG and WebP compress. When you press the resize button the tool processes each image in turn, shows a live progress bar, writes the result into a ZIP, and downloads it. You can also grab any single image on its own without zipping. Your settings are remembered in this browser so the next batch starts where you left off.

Example

Say you have 40 photos straight off a phone, each around 4000×3000 pixels and 3–5 MB, and a web gallery that wants images no wider than 1280px. Choose Fit, set max width and height to 1280, pick JPEG at 82% quality, and click resize. Every photo is scaled down so its longest edge is 1280px, re-compressed, and dropped into one ZIP.

Setting	Value	Result
Mode	Fit inside 1280×1280	Longest edge becomes 1280px, ratio kept
Format	JPEG, 82% quality	Photos shrink from ~4 MB to a few hundred KB
Output	One ZIP	All 40 images in a single download

A typical batch like this drops a folder from well over 100 MB to under 10 MB, often 90% smaller, while still looking sharp on screen — and every byte of the work happens on your own machine.