Image Resizer

Our Image Resizer changes the pixel dimensions of a JPG, PNG, WEBP, GIF, or BMP image — width, height, or both. Pick a mode (Fit, Fill, or Stretch) to control how the image fills the target box, and use the aspect-lock toggle to keep proportions when you only specify one dimension.

How to Use the Image Resizer

1. Upload Your Image

• Drag and drop a JPG, PNG, WEBP, GIF, or BMP file onto the drop zone
• Or click to browse and select a file from your device
• Files up to 10MB are supported

2. Set Target Dimensions

• Enter a width and/or height in pixels (1–8000)
• Leave one field blank to scale only on the other axis (aspect-lock recommended)
• Choose a mode:
  • Fit — scales the image to fit inside the target box, preserving aspect ratio
  • Fill — scales the image to cover the target box and crops the excess from the center
  • Stretch — scales to the exact target dimensions, ignoring aspect ratio
• Toggle Lock aspect ratio to compute the missing dimension from the source image

3. Preview and Download

• The resized image keeps the same file format as the original
• The filename is suffixed with the new dimensions (for example, photo-1920x1080.jpg)
• Download with one click

Key Features

Three Resize Modes

• Fit keeps the entire image visible inside the target box. Best for thumbnails, previews, and any case where cropping is unacceptable.
• Fill covers the target box and crops the excess from the center. Best for avatars, hero images, and any case where the box must be exactly filled.
• Stretch produces the exact target dimensions regardless of source aspect. Best for canvases, templates, and fixed-size placeholders.

Smart Single-Dimension Resize

• Enter only a width or only a height — the other dimension is computed from the source aspect ratio
• Turn aspect-lock off to keep the missing dimension equal to the source (handy for "scale to 800px wide, keep the original height")

Server-Side Performance

• Downscales use PHP's imagescale() for a fast, bilinear result
• Upscales use imagecopyresampled() with a true-color canvas to avoid quality loss
• Target dimensions are capped at 8000×8000 to keep resize times reasonable

Format Preservation

• The resized file uses the same format as the original (JPG → JPG, PNG → PNG, etc.)
• PNG, WEBP, and GIF keep their transparency
• JPG and BMP have transparent pixels filled with white (those formats don't support transparency)

Use Cases

1. Web Publishing

• Resize photos to a max width (for example 1920px) before uploading to a CMS
• Generate multiple smaller sizes for responsive srcset attributes
• Produce thumbnails for galleries and product listings

2. Social Media

• Resize an image to a platform's recommended pixel size (Instagram square, Twitter header, etc.)
• Use Fill mode to crop a portrait photo into a landscape header

3. Email and Chat

• Shrink large images so they fit under common attachment or message size limits
• Resize before compressing to keep quality higher at a smaller file size

4. Print Preparation

• Upscale a low-resolution source to a print-ready size (note that upscaling does not add detail)
• Downscale a high-resolution scan to a shareable size

5. App and Design

• Produce square avatars from rectangular photos (Fill mode)
• Generate icon-sized versions of larger source assets (Fit mode)
• Standardize screenshots to a fixed canvas size (Stretch mode)

Technical Features

• Server-Side Processing: Resize runs on the server with PHP's GD extension — accurate and reliable
• Quality: JPG and WEBP output use a fixed high-quality setting (90%); the resizer is a single-knob tool focused on dimensions
• Automatic Cleanup: Uploaded files are processed and discarded, not retained
• Same-Format Output: No format conversion happens — what you upload is what you download

Why Use Our Image Resizer

1. No Software Required

• Works entirely in your browser — no image editor or codec installation needed
• No signup, no account, no watermarks

2. Three Modes, One Tool

• Fit, Fill, and Stretch cover the vast majority of resize use cases
• Aspect-lock makes single-dimension resizes behave the way you'd expect

3. Fast and Free

• Instant processing for typical image sizes
• Completely free, with no usage limits beyond the 10MB file size cap and 8000×8000 dimension cap

Understanding Image Resize Modes

Fit

Scales the image so it fits entirely inside the target box, preserving aspect ratio. The output may be smaller than the box if the source and target aspect ratios differ. Choose Fit when you need the entire image visible and don't mind whitespace or letterboxing.

Fill

Scales the image so it covers the target box, preserving aspect ratio, and crops the excess from the center. The output is always exactly the target dimensions. Choose Fill when the target box must be exactly filled and cropping the edges is acceptable.

Stretch

Scales the image to the exact target width and height, ignoring aspect ratio. The image may look distorted if the source and target aspect ratios differ. Choose Stretch for canvases, templates, or fixed-size placeholders where the dimensions matter more than the proportions.

Limitations

• This tool accepts JPG, PNG, WEBP, GIF, and BMP. HEIC, TIFF, and SVG are not accepted directly — to resize one of those, first run it through the Image Converter to flatten it to a raster format, then upload the result here.
• Maximum output is 8000×8000 pixels.
• Upscaling cannot add detail that wasn't in the original. A 400×300 image upscaled to 1600×1200 will look soft, not sharp.

Remember: resizing only changes the pixel dimensions. It does not change the file format, color profile, or compression — for those, use the Image Converter.