Queued
Private browser tool
Resize Image
Scale JPG, PNG, and WebP image dimensions by exact pixels or percentage. Fast, local image resizing powered by Lanczos3 WebAssembly sinc resampling.
Resize single photos or bulk batches directly in your browser with zero server uploads and complete privacy.
Image Resizer
Advanced settings
100% Private. Lanczos3 resizing runs directly on your device without uploads.
No paywalls. Unlimited image resizing with zero resolution locks.
Pixel-precise dimension scaling
High-resolution photos from modern smartphones and digital cameras frequently exceed 4000 pixels in width, which is far too large for email attachments, social media avatars, and responsive web pages.
WebpForge resizes images locally on your computer using multi-threaded Web Workers, eliminating the time spent uploading massive files to third-party cloud servers.
- By pixels: Set specific width or height targets with aspect ratio locking for exact layout constraints.
- By percentage: Scale mixed-resolution image collections uniformly by 25%, 50%, or 75%.
- Format flexibility: Retain the original format or transcode directly to WebP, JPG, or PNG during resizing.
Lanczos3 reconstruction filter
Standard HTML5 canvas resizing uses basic bilinear interpolation, which causes noticeable softness and loss of fine line contrast when scaling down high-resolution images.
WebpForge integrates the Lanczos3 windowed sinc filter compiled to WebAssembly. Lanczos3 evaluates a three-lobed sinc kernel to reconstruct image frequencies, ensuring sharp edges, readable typography, and smooth diagonal lines.
Practical examples
- Situation
- A 6000 × 4000 camera photograph needs to fit a standard 1200 px website column.
- Setting
- Width set to 1200, Height set to Auto, Maintain aspect ratio checked.
- Expected result
- A scaled 1200 × 800 image with sharp details and significantly reduced file size.
- Situation
- A batch of 30 mixed-size product images needs to be reduced by half for an email newsletter.
- Setting
- Mode set to By percentage, Scale set to 50%.
- Expected result
- Every image scaled to exactly half its original width and height, downloaded as a ZIP.
- Situation
- A PNG screenshot needs to be scaled down and saved as a lightweight JPG.
- Setting
- Width set to 800, Output format set to Convert to JPG.
- Expected result
- A compact 800 px wide JPG file ready for instant sharing.
Continue with purpose
Related tools and guides
Clear answers
Frequently asked questions
How does WebpForge prevent blurring during image resizing?
WebpForge compiles the Lanczos3 windowed-sinc resampling filter to WebAssembly. Unlike standard browser bilinear downscaling which causes softness, Lanczos3 calculates high-frequency edge gradients to keep fine details and text crisp.
Can I resize images by percentage instead of exact pixels?
Yes. Choose "By percentage" in the mode selector and pick 25%, 50%, 75%, or any custom percentage. Every image in your batch will be scaled down proportionally based on its individual native dimensions.
Will resizing change the aspect ratio or distort the image?
By default, "Maintain aspect ratio" is checked. When you enter a width, the height is automatically calculated to preserve exact source proportions, preventing any squishing or stretching.
How do I download multiple resized images?
When resizing more than one file, a "Download all as ZIP" button appears automatically. WebpForge packages all processed images into a clean ZIP archive directly in your browser memory.