Resize Image by Longest Side
Resize or change image size by setting a single max dimension (longest side). Resize JPG, resize PNG, resize WebP to 1200px, 1600px, 1920px, 2048px and more. Export JPG/PNG/WebP.
Click to select or drag and drop images
Supports JPG, PNG, WebP, AVIF, GIF, HEIC, and more (max 50MB each)
Resize tools by intent
This page targets “one-number resize” searches like “resize image to 1600px” or “set longest side 1920”.
Resize to a max dimension (longest side)
Set the longest side to 1600px and we’ll calculate the other dimension automatically. This is perfect when you want a “max size” and don’t care about exact width/height.
Websites
Use 1200px or 1600px longest side for fast-loading web images.
Social sharing
Use 1080px–1920px longest side for crisp posts and stories.
Screens
Use 1920px longest side for Full HD-friendly images.
Mixed photos
Great for batches with mixed portrait + landscape orientations.
Popular longest-side sizes
- 1200pxCommon for blogs and general web uploads.
- 1600pxHigh-quality web without heavy file sizes.
- 1920pxFull HD friendly for screens and presentations.
- 2048pxCommon “max dimension” requirement for many platforms.
Example (auto-calculated)
If your photo is 4000×3000 and you set the longest side to 2000px, the result becomes 2000×1500. If it’s 3000×4000 (portrait), the result becomes 1500×2000.
Frequently Asked Questions
What does “resize by longest side” mean?▼
It means you set the maximum dimension in pixels (like 1600px). The image is resized so the longer side becomes that number, and the shorter side is calculated automatically.
Is “longest side” the same as “max width/height”?▼
Yes. It’s often described as setting a max width or max height — whichever is larger becomes the target size.
Will this keep aspect ratio?▼
Yes. Longest-side resizing preserves the original aspect ratio automatically for every image.
What size should I use for the longest side?▼
Common values are 1200px for web images, 1600px for high-quality web, 1920px for Full HD displays, and 2048px for many marketplace uploads.
Can I resize JPG, PNG, and WebP with this tool?▼
Yes. You can resize JPG, resize PNG, resize WebP and export to JPG/PNG/WebP with optional quality control for JPG/WebP.
Set your max size and download
Enter a longest-side value, choose format, and export.