Compress Image
Compress one image with a live preview, or drop multiple files or a folder and choose the target size before the batch starts.
- Browser-only
- No upload
- No login
- No watermark
- Clear instantly
- Open-source engines
Drop files here
One image opens live preview. Multiple files or folders use batch mode - .jpg, .jpeg, .png, .webp
Files stay in this browser tab.
Live preview and batch compression run locally in this browser. Nothing is uploaded.
Deep dive
What is Compress Image?
Image compression reduces file size while keeping the image visually similar to the original. Smaller images upload faster, load faster on websites, and take up less storage — without the visible quality loss of resizing.
FormatSwitch compresses JPG, PNG, and WEBP files locally with browser encoders. Single images show a live preview; multiple files and folders use target-size batch compression without upload.
When to use it
- Shrink photos for email attachments or web upload forms.
- Reduce image size before adding to a blog post or product page.
- Free up phone or laptop storage without losing photos.
- Prepare screenshots for bug reports and support tickets.
How to use it safely without uploading
Drop one image to use the live quality slider. Drop multiple images or a folder to choose a target size per image, then run the batch and download a ZIP that preserves folder paths.
Browser-based vs server-based conversion
Most online converters upload your files to their servers, process them there, and then let you download the result. That means your file exists on someone else's computer, often in logs and backups, sometimes indefinitely. FormatSwitch is different: every conversion runs on your device using WebAssembly and the browser's built-in Canvas and PDF engines. Your file never leaves your computer, so there is nothing to leak, nothing to subpoena, and nothing to trust us on — the code that does the work is running right in your tab.
FAQ
Compress Image — questions people ask
- Can I compress images without upload?
- No. Files are processed entirely in your browser using WebAssembly and the Canvas API. Nothing is uploaded to a server, and no copy is kept once you close or refresh the tab.
- Which formats are supported?
- JPG, PNG, and WEBP are supported. PNG inputs that need compression are saved as WEBP because browser PNG encoding is lossless and ignores quality settings.
- Will the images look worse?
- Lower slider values create smaller files with more compression. Keep the slider higher when you need maximum fidelity.
- Is there a watermark?
- Never. FormatSwitch adds no watermark, logo, or quality cap to your output — the file you download is only what your browser produced.
- Does it work on mobile?
- Yes. Every tool runs on modern iOS Safari and Android Chrome. Very large files may be slower on mobile because of tighter memory limits.
- Are my images stored anywhere?
- No. Files live only in your browser's memory (JavaScript heap). They disappear when you clear the queue, refresh, or close the tab. There is no server, no database, no log.