Image Size Reducer

Reduce image size online. No upload ever.

Compress JPEG, PNG, and WebP images for web, email, or social media. Everything runs in your browser, nothing uploaded.

Processing securely on your device, no data sent to any server

Drop your images here

JPG · PNG · WebP · SVG

Privacy Note: We use your browser's hardware to process this file. Your image stays on your computer throughout the entire process, nothing is transmitted.

No upload·100% private·Instant

How it works

Three steps. Done in your browser.

Drop your image

Drag any JPEG, PNG, or WebP onto the zone or click to browse. No file size limit, all processing stays local.

Adjust the quality

The slider controls how aggressively image data is reduced. Quality 80 is a reliable starting point for most images.

Save the result

Compare sizes with the before/after slider, then save your smaller image. No data leaves your device at any point.

Why it matters

Situations where image size creates real friction.

A modern smartphone photo is 4-10 MB. For most destinations, it is 10x larger than needed. Reducing image size eliminates the friction that oversized files cause at every step.

Email attachments

Gmail caps attachments at 25 MB, Outlook.com at 20 MB, and many corporate mail servers at 10 MB. A 2 MB compressed image is universally easier to send than an 8 MB original.

Website and CMS uploads

WordPress, Squarespace, and most CMS platforms enforce upload size limits, often 2-10 MB. Reducing image size before uploading avoids rejected uploads and speeds up page load times.

Social media

Instagram, Facebook, and LinkedIn recompress images on upload. Pre-compressing at your chosen quality gives you more control over the final result rather than letting the platform decide.

Messaging apps

WhatsApp compresses images automatically, often significantly. Sharing a pre-compressed image preserves more detail than letting the app crush it, and uses far less mobile data.

Web performance and SEO

Google uses page speed as a ranking factor. The largest images on a page directly affect Largest Contentful Paint (LCP). Smaller images improve Core Web Vitals scores and search rankings.

Cloud storage management

Backing up photos to Google Photos, iCloud, or Dropbox? Reducing sizes before backup can save gigabytes of storage over time, and speeds up syncing across devices.

How image size reduction works under the hood.

Unlike most online tools that upload your file to a remote server, this compressor runs entirely in your browser tab. For JPEG and WebP, it uses the browser's native Canvas API to re-encode the image at your chosen quality level. For PNG, it loads pngquant as a WebAssembly module and applies lossy palette quantisation, reducing 16.7 million possible colours down to an optimal 256-colour set.

Your file never leaves your device. There is no upload, no server, and no risk of your images being stored or accessed by anyone else. Closing the tab immediately clears all image data from browser memory.

Common questions

Questions answered.

How much can you reduce image size without losing quality?

For JPEG and WebP images, you can typically reduce file size by 60-80% at quality 75-85 with minimal visible quality loss at screen sizes. PNG can be reduced by 40-70% using colour quantisation. The quality slider lets you find the right balance.

What is the difference between reducing image size and resizing an image?

Reducing image size (compression) makes the file smaller in kilobytes while keeping the same pixel dimensions. Resizing changes the pixel dimensions, which also makes the file smaller but changes how large the image appears. For web performance, you often want both: resize to the correct display dimensions, then compress to reduce the file size further.

Which format gives the smallest file size?

WebP typically produces the smallest files, 25-35% smaller than JPEG and 25% smaller than PNG at equivalent quality. If you are not restricted to a specific format, converting to WebP will give you the smallest file.

Is my image uploaded to a server?

No. All compression happens in your browser using the Canvas API and pngquant WASM for PNG. Your file never leaves your device.

Can I reduce multiple images at once?

Yes, with no batch limit. Drop as many files as you need. All processing runs locally in your browser.

Does reducing image size change the pixel dimensions?

No. This tool reduces file size in bytes only. A 4000x3000 pixel image remains 4000x3000 pixels after compression. To change pixel dimensions, use the Resize Image tool.

What quality setting should I start with?

Quality 80 is a good starting point for most images. At quality 80, JPEG and WebP files are typically 50-70% smaller than quality 100 with no visible loss at screen sizes. If the result looks identical to the original, try lowering to 70.

Can I preview the quality before saving?

Yes. Each file card shows original and compressed sizes with the percentage reduction. Click the image preview to open the before/after comparison slider and compare quality before saving.

Related tools

More tools you might need.

Compress Image

Reduce JPEG, PNG, WebP and SVG file sizes by up to 90%, all in your browser.

Compress JPEG

Reduce JPEG file sizes with fine-grained quality control. Fast, free, private.

Compress PNG

Shrink PNG files by up to 80% using pngquant quantisation, no upload.

Convert to WebP

Convert JPEG or PNG to modern WebP, up to 35% smaller at the same quality.