Compress images without guesswork.

Start with the real requirement

Before compressing an image, decide where it will be used. A passport-style upload form, an email attachment and a full-width website photograph do not need the same dimensions. If a service specifies a maximum width, height or file size, use that requirement as the target instead of repeatedly lowering quality.

Dimensions usually matter more than people expect

A 4000×3000 photo contains twelve million pixels. If the final display only needs about 1200 pixels across, keeping all twelve million pixels wastes space. Reducing width and height lowers the amount of image data before compression is even applied. For ordinary web use, this often gives a cleaner result than keeping huge dimensions and forcing JPEG quality very low.

What the quality setting does

JPEG and WebP use lossy compression. A lower quality setting usually creates a smaller file by discarding more visual detail. The exact result depends on the image: photographs with gradients and texture behave differently from screenshots, logos or text-heavy graphics. There is no universal percentage that is best for every picture.

A practical workflow is to resize first, export around a moderate quality level, then inspect the output. If the file is still too large, reduce quality gradually. Avoid jumping straight to an extremely low value because blockiness, ringing around edges and smeared text can become obvious.

JPEG or WebP?

JPEG is widely compatible and remains a safe choice for photographs. WebP often produces competitive file sizes at similar visual quality in modern browsers and apps. If the destination explicitly requires JPG/JPEG, use JPEG. If you control the website and modern-browser compatibility is acceptable, WebP can be useful.

Keep aspect ratio unless you mean to crop

The aspect ratio is the relationship between width and height. Changing only one dimension while forcing the other independently can stretch faces, circles and text. NexusNova's image tool can keep the ratio linked so changing width automatically calculates a matching height. If you need a different shape, cropping is normally preferable to stretching.

Privacy and local processing

The NexusNova image compressor performs its resize/export operation in the browser. The selected image is decoded on your device and the output is generated from a browser canvas. The current tool does not require uploading the file to a NexusNova server. That design is useful when you simply need a smaller file without handing the original image to an additional processing service.

A repeatable compression checklist

• Read the destination's width, height, format and file-size limits.
• Resize oversized images before aggressively reducing quality.
• Keep aspect ratio enabled unless distortion is intentional.
• Choose JPEG when broad compatibility or a JPG requirement matters.
• Try WebP when modern web delivery and smaller files are priorities.
• Open the output and inspect faces, text and fine edges before submitting it.

Why file size can vary even at the same settings

Compression is content-dependent. A smooth blue sky has less visual complexity than tree leaves, fabric patterns or text. Two images with identical dimensions and quality settings can therefore produce very different file sizes. Treat the final output size and visible quality as the result to judge, not the quality percentage alone.