Free Online Bulk Image Resizer Tool for Multiple Images
Bulk image resizer lets you resize multiple images simultaneously with custom dimensions. Set width, height, maintain aspect ratio, choose output format, and download all resized images instantly. No upload, no server, fully private and free.
Upload and Resize Your Images
Resized Images
How to Use the Bulk Image Resizer
Upload Your Images
Click the upload area or drag and drop multiple images. Supported formats include JPG, PNG, WEBP, BMP, and GIF.
Set Target Dimensions
Enter your desired width and height in pixels. Toggle the aspect ratio lock to maintain original proportions automatically.
Choose Output Format
Select your preferred output format from JPG, PNG, or WEBP depending on your use case and quality requirements.
Click Resize All
Click the Resize All Images button to process all uploaded images simultaneously with your chosen settings.
Download Resized Images
Download each resized image individually or click Download All to save every processed image at once.
Key Features of Bulk Image Resizer
100% Free Forever
Resize unlimited images without any charges, subscriptions, or hidden fees. Completely free for everyone.
Pixel-Perfect Accuracy
Get exact dimensions you specify with high-quality browser-native rendering and interpolation algorithms.
Lightning Fast Processing
Resize dozens of images in seconds using optimized client-side Canvas API processing in your browser.
Complete Privacy Protection
Zero server uploads. All images are processed locally in your browser and never leave your device.
No Signup Required
Start resizing immediately without creating accounts, logging in, or providing any personal information.
Mobile Friendly Design
Works perfectly on smartphones, tablets, and desktops with responsive touch-optimized interface.
How Bulk Image Resizing Works
New Height = Original Height × (Target Width ÷ Original Width)Resizing Process Components
- Canvas API Rendering: The HTML5 Canvas element draws each image at the target dimensions using browser-native rendering for optimal quality.
- Aspect Ratio Calculation: When locked, the tool calculates the proportional dimension based on the ratio between original width and height.
- Format Conversion: The canvas toDataURL or toBlob method converts the resized canvas content to your chosen output format (JPG, PNG, or WEBP).
- Quality Compression: For JPG and WEBP formats, the quality parameter controls compression level, balancing file size against visual fidelity.
- Batch Processing: Images are processed sequentially to prevent browser memory overload, with progress tracking for each image in the queue.
When you resize an image, the browser creates an off-screen canvas element at your target dimensions. The original image is then drawn onto this canvas, and the browser's rendering engine handles pixel interpolation. For example, if you are resizing product images for your Flipkart or Amazon India listing from 4000x3000 pixels to 1000x750 pixels, the browser smoothly downscales each pixel to produce a clean, sharp result. The resized image is then encoded in your chosen format and made available for download.
Practical Bulk Resizing Examples
E-commerce Product Photos
Settings: Width 1000px, Height auto (aspect locked), JPG 92% quality
Result: 25 images resized to 1000×750px, average 120KB each
Use Case: Rajesh from Mumbai uploads product images to his Meesho and Amazon India stores, reducing each from 5MB to 120KB for faster listing loading.
Social Media Batch Content
Settings: Width 1080px, Height 1080px (aspect unlocked), PNG
Result: 15 square images at 1080×1080px for Instagram posts
Use Case: Priya, a digital marketing executive in Bengaluru, prepares a week's worth of Instagram content by batch resizing all photos to square format in one click.
Website Blog Image Optimization
Settings: Width 800px, Height auto (aspect locked), WEBP 85% quality
Result: 10 images at 800×450px, average 35KB each in WEBP
Use Case: Amit runs a travel blog from Delhi and optimizes all article images to WEBP format, improving his PageSpeed score from 62 to 94.
WhatsApp Business Catalogue
Settings: Width 600px, Height 600px (aspect unlocked), JPG 90%
Result: 30 uniform catalogue images under 80KB each
Use Case: Sunita from Jaipur runs a handicrafts business on WhatsApp and needs uniform-sized product images for her business catalogue that load quickly on customers' phones.
What is a Bulk Image Resizer?
A Bulk Image Resizer is a specialized tool designed to resize multiple images simultaneously, saving you hours of manual work compared to editing each image one by one in photo editing software. Whether you are an e-commerce seller preparing product listings, a blogger optimizing website images, a social media manager creating content, or a student preparing project presentations, this tool streamlines your image processing workflow dramatically.
Our free online Bulk Image Resizer at StoreDropship processes everything directly in your web browser using the HTML5 Canvas API. This means your images never leave your device, ensuring complete privacy and security. Unlike server-based tools that upload your files and may retain copies, our tool guarantees zero data transmission. This is particularly important for businesses handling confidential product images before launch or individuals working with personal photographs.
The tool supports all popular image formats including JPG, PNG, WEBP, BMP, and GIF for input, and offers JPG, PNG, and WEBP as output options. With features like aspect ratio locking, adjustable quality compression, and batch download capability, it delivers professional-grade results that rival expensive desktop software. Built with expertise in web technologies and image processing, this tool has been designed following industry best practices for accuracy, performance, and user experience. Indian users especially benefit from the fast client-side processing since it works perfectly even on slower internet connections common in Tier 2 and Tier 3 cities.