Image Compressor

Re-encode a photo at a quality you choose and watch the file size fall, with the original and the compressed version shown side by side before you download.

What is the Image Compressor?

JPG, WebP and AVIF are lossy formats: the encoder discards detail the eye is least likely to miss, and a quality number decides how much of it goes. This tool re-encodes your image at the quality you set while keeping the original pixel dimensions, then reports the reduction, the bytes saved and the ratio. PNG works differently because PNG is lossless, so there the slider controls how many colors survive, using UPNG to quantize the palette.

Key Features

• Quality slider from 10 to 100 percent, defaulting to 80
• Outputs JPG, PNG or WebP, plus AVIF where the browser can encode it
• Keeps the original pixel dimensions, changing only the encoding
• Side-by-side original and compressed previews with both file sizes
• Reduction percentage, bytes saved and compression ratio shown together

Common Use Cases

• Getting a camera photo under an upload limit on a form or portal
• Converting a set of product shots to WebP for a faster storefront
• Cutting page weight on a blog post that carries several large photos
• Reducing an oversized email attachment without cropping or resizing it

How to Use the Image Compressor

1. Drop an image onto the upload panel, or click it to browse for one.
2. Choose the output format: JPG, PNG, WebP, or AVIF if it is offered.
3. Drag the quality slider and watch the compressed preview and size update.
4. Compare the two previews closely for smearing around text and sharp edges.
5. Click Download Compressed Image once size and quality both look right.

Tips for Best Results

• Around 75 to 85 percent is the usual sweet spot for photographs on the web
• Always compress from the original file, since re-saving a JPG loses detail every time
• Use PNG for screenshots and flat graphics, because JPG smears text edges badly
• If the AVIF button is missing, your browser cannot encode it, so try WebP

Why Use WiserWork's Image Compressor?

The quality number in a JPG encoder is not a percentage of anything visible, which is why guessing at it is hopeless and seeing both versions at once is not. Here you move the slider and immediately see what it cost. Everything runs on a canvas in your own browser, so holiday photos and client work are never handed to a server.

Who Uses the Image Compressor?

Bloggers and shop owners trimming page weight are the most frequent users, along with anyone fighting an upload size limit. Developers use it to spot-check what a format switch would save before wiring up a proper image pipeline.

Frequently Asked Questions

Why does saving a JPG again and again make it worse?

Each save is a fresh lossy encode of an already-damaged image, so the artifacts compound. This is generational loss, and it is why you should always start from the original file.

What file size should I aim for on the web?

For a full-width photograph, roughly 100 to 300 KB is a common target, and thumbnails should sit well under 50 KB. Your overall page weight budget matters more than any single number.

Does compressing change the image dimensions?

No. The canvas is created at the source image's natural width and height, so only the encoding changes. Use the resizer if you need fewer pixels.

Why did my file get bigger instead of smaller?

You most likely re-encoded an already-compressed JPG at a higher quality, or chose PNG for a photograph. The reduction figure turns negative when that happens.

How does the quality slider work for PNG?

PNG is lossless, so the format has no quality knob. Below 95 percent the tool quantizes the palette with UPNG, mapping the image to roughly 30 up to 256 colors; at 95 and above it keeps full color.

Why is the AVIF button sometimes not there?

The page tests whether your browser can encode AVIF on a one-pixel canvas and shows the button only if it can. Safari generally cannot, so the option stays hidden.

What happens to a transparent PNG if I output JPG?

JPG cannot store transparency, so transparent areas get flattened, typically to black. Choose PNG or WebP when the image has to keep its transparent regions.

Are my photos uploaded?

No. The image is drawn to a canvas element in your browser and re-encoded there. Nothing is sent anywhere, and no watermark is added to the result.

Is any metadata kept?

No. Re-encoding through a canvas discards EXIF data, so camera settings, timestamps and GPS coordinates do not survive. That is often exactly what you want before publishing.

Which format should I pick?

WebP for most web images, since it beats JPG at the same visible quality. JPG for maximum compatibility, and PNG for screenshots and graphics with flat color and sharp edges.

Compression is a trade you make deliberately, not a setting that gets it right for you. Move the slider until the preview stops looking acceptable, then step back one notch and save that.