Free Image Compressor

How to Compress an Image

1. Upload your images — Click Select Images or drag and drop files directly onto the upload area. The tool accepts JPG, PNG, WebP, and GIF files up to 30 MB each. You can upload multiple files at once.
2. Compression starts automatically — There is no button to click. As soon as your files are uploaded, the tool begins compressing them one by one. Each row shows a spinner while the file is being processed.
3. Check the results — Each image shows the original size, the compressed size, and the percentage saved. The totals strip at the top updates as each file finishes so you can see the combined savings across your entire batch.
4. Download your files — Click Save on any individual row to download that file, or use Save All to download every compressed file at once. Use Download ZIP to get all files in a single archive.

What the Image Compressor Does

JPG Compression

JPG files are compressed by re-encoding the image at a carefully selected quality level. The tool tries multiple quality settings — from 82 down to 68 — and picks the smallest output that is still smaller than your original. It also automatically strips embedded EXIF and ICC metadata that cameras and editing software add to photos. That metadata alone can add 50 to 200 KB to a photo without contributing anything to the visual image. The result is a smaller file that looks identical to the original in a browser or on screen.

PNG Compression

PNG compression is more involved. The tool analyses the image to determine how many unique colours it contains, then selects an appropriate compression strategy.

For photos and images with thousands of colours, the tool reduces the colour palette to between 128 and 256 colours using dithering — a technique that blends nearby pixels to simulate colours that are no longer in the palette. This process, similar to what dedicated tools like pngquant use, typically reduces PNG file size by 50 to 90% with no visible degradation on screen.

For logos, icons, and screenshots with fewer than 500 unique colours, the tool can use smaller palettes (down to 32 colours) because simple graphics lose very little visual detail when colours are reduced.

Every compressed PNG is also run through lossless zlib compression using every available filter strategy, and the smallest result across all candidates is selected.

Transparent backgrounds are fully preserved. The tool detects transparency and marks the correct palette colour as transparent in the output, so logos and icons with transparent backgrounds look exactly as intended.

WebP Compression

WebP files are re-encoded at multiple quality levels and the smallest output that beats the original is returned. WebP is already an efficient format, so typical savings are 10 to 30%, depending on the original encoding quality.

GIF Compression

GIF files are re-encoded using lossless palette compression. If the re-encoded file is larger than the original, the original is returned unchanged.

How Much Can You Compress an Image?

Compression savings depend on the image type and how it was originally saved.

If a file cannot be made smaller than the original — for example, a WebP that was already heavily optimised — the tool returns the original file unchanged and marks it as Already optimal.

Does Image Compression Reduce Quality?

It depends on the format.

For JPG: The tool re-encodes at a quality level between 68 and 82. At these levels, the visual difference from the original is not detectable by the human eye under normal viewing conditions. The images look the same on websites, social media, and in email. The difference only becomes visible if you zoom in to 400% or compare pixel values directly.

For PNG: The colour palette reduction used for PNG is technically lossy — the number of distinct colours in the image is reduced. However, because dithering is used and palette sizes are chosen based on the image’s colour complexity, the compressed image looks identical at normal viewing sizes. Icons and logos with flat colours or limited gradients are not affected at all.

For WebP and GIF: Re-encoding at the quality levels used by this tool produces results that look the same as the original.

In all cases, the tool never outputs a file that is larger than the original. If compression does not reduce the file size, the original is returned.

Why File Size Matters

Faster page load times
Images are typically the largest files on any webpage. Compressing images reduces the amount of data a browser has to download before the page can display fully. A page with 2 MB of uncompressed images and 600 KB of compressed images loads in roughly one third of the time on a typical mobile connection.

Core Web Vitals and SEO
Google uses page speed as a ranking signal. Large images that are slow to load directly affect Largest Contentful Paint (LCP), one of the three Core Web Vitals metrics that Google measures. Compressing images is one of the most effective ways to improve LCP without making any changes to your server or code.

Reduced storage and bandwidth costs
If you run a website, every image download costs bandwidth. On high-traffic sites, the cumulative bandwidth saved by compressing images can be significant. Compressed images also take up less storage space in your media library, on your server, and in your backups.

Better user experience on mobile
Mobile connections are slower and more variable than desktop connections. Smaller images load faster, consume less mobile data, and display more quickly — particularly on slower 4G connections or in areas with weak signal.

Email and messaging limits
Many email clients and messaging platforms have attachment size limits. Compressing images before attaching them makes it possible to include more images in a single email without hitting size limits or causing slow send times.

Use Cases

Optimising images before uploading to a website
Before uploading product photos, blog images, or portfolio work to your CMS, compress them to reduce page load times. Most content management systems accept compressed images without any issues, and the visual difference on screen is undetectable.

Preparing images for social media
Platforms like Instagram, Facebook, LinkedIn, and Twitter re-compress images when you upload them. Starting with a smaller, already-compressed image gives the platform less to degrade, resulting in better final quality in your posts.

Reducing email attachment sizes
Compress photos before attaching them to emails to stay within attachment size limits and reduce the time it takes recipients to download the message.

Batch compressing a product image library
Upload an entire folder of product images at once. The tool processes them sequentially and lets you download all compressed files in a single ZIP archive, making it practical to compress large batches without downloading files one at a time.

Speeding up a slow WordPress or Shopify site
Unoptimised images are the most common cause of slow WordPress and Shopify sites. Compress your images before uploading them to your media library or product gallery to reduce page weight without installing additional plugins.

Compressing screenshots for documentation or support tickets
Screenshots from Retina or high-DPI displays are often 3 to 8 MB as PNG files. Compressing them before including them in documentation, support tickets, or Slack messages makes them faster to upload and easier for others to view.

Archiving photos without filling up storage
Compress a folder of photos before archiving them to an external drive or cloud storage. The images will look the same but take up significantly less space.

Image Compression Tips

Compress before uploading, not after
Once an image is already on your website or in a media library, it has often been re-processed by the platform. Compress the original file before you upload it so the platform works with the smallest possible version from the start.

JPG is best for photos, PNG is best for graphics
If you are choosing a format, use JPG for photographs and images with complex colour gradients. Use PNG for logos, icons, screenshots, and images that need a transparent background. Using the right format before compression gives you better results with smaller file sizes.

You do not need to resize the image to save space
Compression and resizing are different operations. This tool reduces the file size of your image without changing its pixel dimensions. If you also need to change the image dimensions, use the image resize tool first, then compress.

Transparent PNG logos compress very well
A PNG logo with a transparent background and limited colours can often be compressed by 80 to 95% with no visible change. If you use logo files regularly for presentations, emails, or documents, keeping a compressed version saves time and reduces friction.

Check the savings badge before downloading
Each image in the list shows a savings badge after compression is complete. If a file shows 0% — Already optimal, the original was already well-compressed and no further reduction was possible. You can still download it and the original will be returned unchanged.

Use Download ZIP for batch downloads
If you compress more than three or four images at once, use the Download ZIP button to get all files in a single archive. Downloading them individually with Save All works fine but takes longer due to the sequential download delays built into browsers.