Compress Images

Shrink Image File Sizes Without the Quality Hit

Large image files slow down web pages, fill up email attachment limits, and eat through cloud storage. This compressor lets you take a folder of oversized JPGs, PNGs or WebP files and bring them down to a fraction of their original weight using two complementary levers: a quality slider that controls how aggressively the encoder discards detail, and resize / max-width options that cut the actual pixel dimensions. You can drop in up to 10 images at a time (10MB each), watch a live estimate of the output size before you commit, and download everything back as a tidy ZIP — all without a single byte leaving your computer.

Behind the scenes, each image is painted onto an HTML5 canvas at the dimensions you choose and re-encoded to your selected format. Because the canvas re-encodes from the decoded pixels, the tool can squeeze redundant data out of photos that were already saved at a high bitrate, while leaving you in full control of the visual trade-off.

Step-by-step: how to compress your images

1. Add your images: Drag and drop them onto the upload area or click to browse. You can mix formats — JPG, PNG, WebP, GIF and BMP are all accepted. A thumbnail and the original file size appear for each one.
2. Set the quality: Move the quality slider (10–100%). Lower values throw away more detail and produce smaller files; higher values stay closer to the original. For most photos, 70–80% is the sweet spot.
3. Choose an output format: Keep the original format, or convert to JPG (great for photographs), PNG (for sharp graphics and transparency), or WebP (modern, smallest files).
4. Optionally resize: Use the resize slider to scale every image to a percentage of its original dimensions, or pick a Max Width (1920, 1280 or 800 px) to cap how wide the longest images can be. Shrinking the pixel count is often the single biggest file-size win.
5. Read the live estimate: A line below the settings predicts the output size and how much smaller (or larger) it will be, based on your first image, so you can tune settings before processing.
6. Compress and download: Click Compress Images. Each result card shows the percentage reduction and the before/after sizes. Download files individually, or grab them all at once as a ZIP.

When this tool is the right choice

• Speeding up a website or blog: Page-load times improve dramatically when hero images and galleries are resized to the width they actually display at and compressed to 75–85% quality.
• Beating email and upload limits: A 9MB photo that won't attach can usually be brought under 1MB without anyone noticing the difference on screen.
• Preparing product or listing photos: Marketplaces and CMS platforms often cap file sizes; batch-compressing a set keeps them consistent and compliant.
• Trimming cloud and device storage: Re-saving a phone-camera dump at 80% quality and 1920px max width can reclaim a surprising amount of space.
• Sending screenshots or documents quickly: Convert bulky PNG screenshots to JPG or WebP to share them faster over chat.

Tips and best practices

Match the format to the content. Photographs and anything with smooth gradients compress best as JPG or WebP, where small color changes can be discarded invisibly. Logos, icons, screenshots of text, and images that need a transparent background belong in PNG (or WebP), because JPG will smear sharp edges and can't store transparency.

Resize before you obsess over quality. A 4000px photo displayed in a 1000px column is carrying four times more pixels than it needs. Capping the Max Width or lowering the resize percentage usually saves more weight than any quality setting — and it does so with zero visible loss at the size it's actually shown.

Use WebP when your audience's browsers support it. WebP typically produces noticeably smaller files than JPG at the same perceived quality and is supported by every current major browser. If you need maximum compatibility with very old software, stick with JPG.

Don't compress the same JPG twice. Each re-encode of a lossy format discards a little more detail. Always start from the highest-quality original you have rather than re-compressing an already-compressed file.

Watch the quality cliff. Below roughly 50–60% quality, JPG and WebP start to show blocky artifacts and color banding, especially in skies and skin tones. Nudge the slider down gradually and check the result size estimate rather than jumping straight to the lowest setting.

Common problems and how to fix them

Re-encoding PNG does not necessarily reduce its bytes, and JPEG quality settings do not control PNG encoding. Consider smaller dimensions or another accepted format. When the same-format result is larger, the tool retains the original; that size comparison does not assess visual quality.

"The compressed image looks soft or blocky." You've pushed the quality slider too low for that image. Raise it back toward 75–85%, and consider resizing instead, which reduces file size without introducing compression artifacts.

"A file was rejected." Each image must be 10MB or smaller, and you can process up to 10 at once. Compress very large files in smaller batches.

"Transparency disappeared." JPG cannot store transparent pixels — they become a solid background. Choose PNG or WebP as the output format to preserve transparency.

How it works in your browser

Everything happens on the device in front of you. When you add images, they're read into memory with the browser's FileReader and drawn onto a canvas element; the canvas then exports the pixels at your chosen format and quality. The ZIP for "download all" is assembled in-browser with JSZip. At no point are your images transmitted to QuickMerge or any third party — there is no upload step, no server-side processing, and nothing stored after you close the tab. That makes the tool safe for compressing private documents, screenshots, ID photos, or any image you'd rather not hand to an online service.

Next steps