What it does
Image Converter and Compressor is a free, browser-based tool for converting images between formats and reducing file sizes. You pick a target format (JPG, PNG, or WebP), set a quality level, optionally resize by width, and download — individually or as a single ZIP. It handles photographs, screenshots, logos, and anything else your browser can decode.
It works on desktop and mobile, requires no account, and installs nothing. Open the page, drag your files in, and you're done.
How it works
Everything happens in your browser using the Canvas API. When you add an image, the browser decodes it into raw pixel data, optionally scales it, then re-encodes it to the format and quality you chose. The result is a new file created entirely on your device.
There is no server involved. Your images are never uploaded anywhere. The only network requests the page makes are to load fonts from Google Fonts — the images themselves do not leave your machine at any point.
This also means the tool keeps working if your internet connection drops mid-session. Once the page is loaded, it runs offline.
Supported formats
Input (what you can open)
The tool accepts any image format your browser can decode: JPG, PNG, WebP, GIF, and BMP. Most modern browsers also handle AVIF. What you cannot open: HEIC/HEIF (common on iPhones), camera RAW files (CR2, NEF, ARW, etc.), or TIFF — these require native OS codecs that browsers don't expose. See the format troubleshooting guide for workarounds.
Output (what you can export)
You can export to JPG, PNG, or WebP. GIF and BMP cannot be exported because the Canvas API doesn't support encoding them. Animated GIFs export as a single still frame — the tool doesn't do animation.
Features
- Batch processing
- Drop up to 200 images at once. They process in parallel (three at a time) and you can download them individually or as a single ZIP.
- Quality slider
- For JPG and WebP, a 0–100 quality slider controls the compression level. PNG is lossless and ignores the slider. The default of 80% is a good starting point for most photos.
- Max-width resize
- Set a maximum width in pixels. Images wider than that are scaled down proportionally before encoding. Images smaller than the limit are left at their original size.
- EXIF orientation
- On browsers that support
createImageBitmap with the imageOrientation option, photos taken in portrait mode on phones are automatically rotated correctly before export.
- ZIP download
- The "Download all (.zip)" button bundles your results into a ZIP file assembled entirely in the browser — no server call needed.
Frequently asked questions
- Is it really private?
- Yes. Images are decoded and re-encoded locally using your browser's built-in engine. Nothing is sent to any server.
- Why did a file get bigger after conversion?
- Converting an already-compressed photo to PNG (which is lossless) will increase the file size. For photos, JPG or WebP at 75–85% quality gives the smallest result. See the format comparison guide for when to use which.
- Can I use it on my phone?
- Yes. The tool is mobile-responsive. Tap the drop zone to open your camera roll or file picker. Large batches may be slower on older phones due to memory limits.
- Why is my HEIC photo not opening?
- HEIC is Apple's format and most browsers on Windows and Android can't decode it without additional codecs. The fix is to export as JPG from your iPhone instead (Settings → Camera → Formats → Most Compatible). The troubleshooting guide covers this in detail.
- What's the file size limit?
- Individual files above 50 MB are skipped. Images with more than 80 megapixels are automatically scaled down to fit within safe canvas memory limits.
- Does it work offline?
- Once the page has loaded, yes. The images themselves never leave your device regardless — but fonts and the page itself require an initial network load.
Who made this?
Image Converter and Compressor is a small independent project. It's supported by advertising — the tool is and will remain free. If you have feedback or find a bug, please get in touch.