---
title: "Resize Images Online — Fast, Private, No Upload | Compress Pro"
description: "Resize images right in your browser — set a longest-side limit like 1920 px and photos scale down with their aspect ratio intact. No uploads, no limits. Free."
canonical: https://compress-pro.com/resize-image
---

# Resize images.

> Downscale photos to any pixel size — all in your browser.

**Shrink image dimensions on your device**: set the longest side — the page starts at 1920 px — and every photo scales down proportionally with smooth, high-quality resampling. The format stays what it was, compression happens in the same pass, and upscaling never happens: images already smaller than the cap pass through untouched.

**No uploads · No ads · Free & open source.**

## How it works

1. Drop files anywhere on the page, click to browse, or paste with Ctrl/⌘ + V.
2. Pick a quality or preset — or set an exact target size and let the tool find it.
3. Compress, compare before/after, and download — individually or as a ZIP.

## How longest-side resizing works

Thinking in “longest side” beats thinking in width×height: one number covers landscape, portrait and square images without distortion. Resizing is also where the big savings hide — a 48-megapixel phone photo holds many times the pixels a 4K screen can even show, so capping it at 1920 px routinely cuts 80–90% of the file before quality settings matter at all. Once the dimensions are right, [compressing the JPG](https://compress-pro.com/compress-jpg) squeezes what remains.

## Common target sizes

| Use | Longest side |
| --- | --- |
| 4K displays and print | 3840 px |
| Web pages & full-HD screens | 1920 px |
| Email and chat photos | 1280 px |
| Thumbnails & avatars | 640 px |

## Resize and compress in one pass

The dimension cap and the quality slider work together in a single encode — there’s no second generation loss from doing them separately. For an upload form with a size cap, combine the cap with target-size mode: quality adapts first, and if you allow downscaling to reach the target, dimensions give way only when quality alone can’t get there.

## Frequently asked questions

### Does resizing keep the aspect ratio?

Always. You set one number — the longest side — and the other dimension follows proportionally. A 4000×3000 photo capped at 1920 px becomes 1920×1440; a portrait becomes 1440×1920.

### Can it enlarge small images?

No — the cap is downscale-only by design. Upscaling invents pixels and makes photos blurry, so images already within your limit are left at their original size.

### Which formats can I resize?

JPG, PNG, WebP, GIF and HEIC — drop any mix. Each keeps its own format by default, animations are resized frame by frame, and you can pick a different output format on the tab if you want conversion too.

### Are my photos uploaded?

No — the pixels never leave your machine. Decoding and re-encoding both happen in your browser; there is no upload to wait for and no server-side copy to worry about afterwards. Want proof? Run one file through, switch your connection off, and run another — it still works.

## Related tools

- [Compress JPG images](https://compress-pro.com/compress-jpg)
- [Compress PNG images](https://compress-pro.com/compress-png)
- [Compress HEIC photos](https://compress-pro.com/compress-heic)

---

Part of [Compress Pro](https://compress-pro.com/) — every tool page has a markdown twin at `<page url>.md`. Full tool index: [llms.txt](https://compress-pro.com/llms.txt)