- FREE ONLINE IMAGE COMPRESSOR · BLOXSTATION
Image Compressor — Free, Fast & Private
Use this image compressor to reduce image file sizes, convert formats and resize pictures directly in your browser. Optimize JPG, PNG and WebP images without uploading your files to a processing server.
- Free to use
- No sign-up required
- Processed locally
- Mobile friendly
Up to 60 images per batch, 60 MB each
Processed Images
Local Processing
Your images are processed in your browser. The tool doesn’t send your files to a server for processing.
Multiple Formats
Work with JPG, PNG and WebP, and convert between formats.
Batch Support
Compress and convert multiple images at once and download them individually or as a ZIP file.
Full Control
Adjust quality, dimensions and output format to find the right balance of file size and clarity.
Works on Any Device
Use it in a modern browser on desktop, tablet or mobile. No installation required.
Table of Contents
What Is an Image Compressor?
An image compressor makes a picture’s file smaller so it loads faster, uses less storage and is easier to share. This free image compressor runs in your browser: add JPG, PNG or WebP files, choose your settings and download the results.
Smaller images help web pages load faster, keep email attachments within size limits and speed up uploads on slow connections. A good image compressor also lets you control quality, so you decide how much detail to trade for file size.
Compress, Resize and Convert Images Online
The tool has three modes, so one image compressor covers the most common image jobs without extra software.
Compress JPG, PNG and WebP images
Open the Compress tab and use the quality slider to lower file size. JPG and WebP are lossy, so a lower quality means a smaller file. PNG is lossless, so the slider has no effect on it.
Resize images to exact dimensions
Open the Resize tab, pick a preset or enter a custom width and height. Choose Crop to fill for an exact size, or Fit to keep the whole picture.
Convert images to WebP, JPG, PNG or AVIF
Open the Convert tab to switch formats. AVIF appears only if your browser can encode it, and JPG output fills transparent areas with white.
How to Use the Image Compressor
Follow these simple steps to optimize your images.
Upload your images
Drag and drop files or click to select supported JPG, PNG or WebP images.
Choose settings
Pick Compress, Convert or Resize, then set quality and output format.
Process images
Click the process button and let your browser do the work.
Review results
Compare file sizes and preview the first processed image.
Download your files
Download individually, or get all processed images as a ZIP.
Why Use the Bloxstation Image Compressor?
A browser-based way to optimize images for websites, email, social posts and documents.
Local processing — Images are decoded, resized and re-encoded in your browser using the Canvas API. The tool does not send your files to a Bloxstation server for processing. Site-wide analytics or advertising scripts, where used, may have their own data practices.
Control over output — Format, quality and dimensions all affect file size and appearance. Lower quality and smaller dimensions generally give smaller files; PNG output is lossless and ignores the quality setting.
Batch workflow — Add up to 60 JPG, PNG or WebP images, apply one set of settings, and download files individually or as a ZIP.
Transparent results — Each file shows original size, new size and percentage change, with a before-and-after preview of the first processed image and a warning if an output is larger.
Practical limitations — Results vary by image, format and settings. JPG cannot store transparency, so transparent areas become white. Very large images use a lot of memory, so images over 12,000 px on a side or 60 megapixels are rejected.
Image Format and Compression Guidance
Which format fits which job, and how each one behaves in this tool.
Format
Good for
Transparency
Compression in this tool
JPG
Photographs and wide compatibility
No (filled with white)
Lossy, controlled by the quality slider
PNG
Logos, screenshots and flat-color graphics
Yes
Lossless, so quality has no effect and files can be large
WebP
General web use
Yes
Lossy, controlled by the quality slider
AVIF
Further size savings where supported
Yes
Lossy; offered only if your browser can encode AVIF
WebP at around 75–85% quality is a reasonable starting point for web images. Compare the before-and-after preview, then lower the quality until you can see a difference and step back up.
Dimensions matter as much as quality. Resizing an image to the size it will actually be displayed at often saves more than the quality slider alone. Keep your original files: re-compressing an already compressed JPG or WebP can add visible artifacts.
Need a document instead of separate images? Use the Bloxstation Image to PDF Converter.
Why Use an Image Compressor Before Uploading to WordPress?
Large images are one of the most common reasons a web page feels slow. Running photos through an image compressor before you upload them keeps your media library lean and your pages lighter.
A simple workflow works well: resize the image to the size it will be shown at, compress it, then upload it. WebP is a good default for website images. Keep your original files in case you need to start again.
Get a smaller file without visible loss
Start around 80% quality and check the before-and-after preview. If you see artifacts, step the quality back up. For PNG graphics, converting to WebP often saves more than any setting.
Learn more about image formats and image SEO
For a deeper look at file types, read MDN’s guide to image file types. Google explains how to help search engines understand your pictures in its image SEO best practices. The Canvas API that processes images locally is documented on MDN.
Explore every free utility on the Bloxstation tools page, or head back to the Bloxstation homepage for more tech and AI guides.
Image Compressor FAQ
Quick answers about the Bloxstation Image Compressor.
How do I compress an image without losing too much quality?
Start with WebP at about 80% quality and check the before-and-after preview. Lower the quality until you notice a difference, then go back up a step. Resizing the image to the size it will be displayed at also reduces file size without touching quality.
JPG, WebP and AVIF are lossy, so some detail is discarded. Keep your original files.
Is this image compressor free?
Yes. It is free to use, with no account and no watermark. The practical limit is the memory available on your device.
Can I compress multiple images at once?
Yes. You can add up to 60 JPG, PNG or WebP images (60 MB each) in one batch, process them with the same settings, and download them individually or as a ZIP file.
Does the image compressor upload files to a server?
No. Images are processed in your browser with the Canvas API, and the tool does not send them to a Bloxstation server for processing.
The page loads a ZIP library from a public CDN. That is code only, and your images are not sent to it. Site-wide analytics or advertising scripts, where used, are separate from the tool and may have their own data practices.
Which image format should I choose?
WebP is a good default for websites. Choose JPG for photos that need the widest compatibility, and PNG for graphics that need transparency or perfectly sharp edges. AVIF appears as an option only if your browser can encode it.
Can I compress PNG images?
Yes, but PNG output is lossless, so the quality slider does not change it and savings can be small. To shrink a PNG more, convert it to WebP (which keeps transparency) or JPG (which does not), or reduce its dimensions on the Resize tab.
How do I resize an image to exact dimensions?
Open the Resize tab, choose a preset or Custom and enter a width and height. Select Crop to fill to get exactly that size. Fit keeps the whole picture, so one side can be smaller than your target.
Why did the output image become larger?
Common causes are a very high quality setting, converting an already well-optimized JPG or WebP to lossless PNG, or resizing to dimensions larger than the original. Try a lower quality, WebP or JPG output, or smaller dimensions. The tool flags results that are larger than the original.
Does converting an image to JPG preserve transparency?
No. JPG cannot store transparency, so this tool fills transparent areas with white. Use PNG or WebP if you need to keep a transparent background.
Ready to compress your images?
Free to use, with processing done in your browser.