Blog
How to Batch Resize PNG and JPG Images Online Free
Resize multiple PNG and JPG images at once. Scale by percentage or set exact pixel dimensions locally in your browser with no upload.
The need for batch image resizing
Whether you are preparing catalog photos for an e-commerce website, uploading images to a blog, or sharing a folder of family photos, processing images one by one is slow and tedious. A batch image resizer lets you upload dozens of images and apply the same size rules to all of them simultaneously.
Many online batch resizers require uploading your entire folder to their cloud server. This is slow because of upload bandwidth and poses privacy concerns. A browser-based batch resizer does the work locally on your device, giving you instant results and total privacy.
Percentage scaling vs exact dimensions
When resizing a batch of images, you can choose between two methods depending on your workflow:
- Percentage Scaling (e.g., 50%): Useful when your source images have different sizes and shapes, and you simply want to scale them all down proportionally (e.g., to make their file sizes lighter for email).
- Exact Dimensions (e.g., 1200px width): Perfect when a platform requires a specific width or height (like a blog content area). You can lock the aspect ratio to prevent the images from looking stretched.
How to batch resize PNG & JPG images locally
Using the PhotoTools Resize tool, you can process multiple files locally in seconds. Follow this simple guide:
- Select and drop multiple JPG, PNG, WebP, or HEIC files into the resizer.
- Choose your resizing mode: Percentage or Pixels.
- Set your target dimensions (e.g., width to 1080px) and toggle the aspect ratio lock.
- Choose your desired output format (JPEG, PNG, or WebP).
- Click Resize all, and download your resized files individually or as a single ZIP archive.
Maintaining aspect ratio to avoid distortion
The aspect ratio is the relationship between an image's width and height. If you force a landscape photo (e.g., 16:9) into a square container (1:1) without cropping or scaling correctly, the photo will stretch and distort.
Always keep the aspect ratio lock enabled when resizing exact pixel dimensions. This lets you input the target width, while the height automatically calculates to match the original proportions, ensuring your subjects look natural.
FAQ
Can I batch-resize different image formats at once?
Yes. You can drop a mix of JPG, PNG, and WebP files. You can convert all of them to a uniform output format (like WebP) or keep their original formats while resizing.
Is there a limit on how many images I can resize?
Since the scaling happens locally using your computer's processor and memory (via HTML5 Canvas API), there is no arbitrary server upload limit. You can easily process 50+ images at a time.
Does batch resizing delete my original files?
No. The tool processes a copy of your files in memory and downloads the resized versions as new files. Your original images remain completely untouched on your device.
Need to resize multiple photos?
Related reading
Frequently asked questions
Can I batch-resize different image formats at once?
Yes. You can upload a mix of JPG, PNG, WebP, and HEIC files, resize them, and export them into your chosen format.
Is there a limit on the number of files I can resize?
There are no server limits because all resizing is done locally on your device. Large batches depend only on your device's memory.
Does resizing distort my images?
No, as long as you keep the aspect ratio lock enabled. The height will automatically scale to match the width, avoiding any stretching.