What It Does

What Is an Image Compressor?

An image compressor is a tool that makes image files smaller without making them look noticeably worse. It does this by reducing the amount of data used to store the image — either by throwing away some details the human eye won't miss (lossy compression) or by encoding the same visual data more efficiently (lossless compression).

The size of your image files has a direct impact on how fast your website loads, how much storage you use, and how smoothly your images send over messaging apps. A 3MB photo straight from your camera might look gorgeous, but it'll slow down a webpage and eat mobile data. The same photo compressed to 300KB looks nearly identical to a human but loads 10x faster.

Best for photos

Lossy (JPEG, WebP)

Removes some visual details that are hard to notice. Gives you the biggest size reductions. Perfect for photos where a small quality trade-off is invisible in normal viewing.

Best for graphics

Lossless (PNG)

Stores the same visual data more efficiently without losing any pixels. File size reduction is more modest but the image is pixel-perfect. Ideal for logos and UI graphics.

Best for web

Modern WebP

Google's format achieves 25–35% smaller files than JPEG at the same quality. Supported by every modern browser and increasingly the default for web images.

Why Compress

Why You Should Compress Your Images

Real-world situations where smaller images make a meaningful difference

Faster Website Loading

Images are the biggest contributor to page weight. Compressing them can cut your page load time in half, directly improving user experience and Google's Core Web Vitals scores.

Better SEO Rankings

Google uses page speed as a ranking signal. Faster pages with optimised images rank higher. Image compression is one of the highest-ROI technical SEO improvements you can make.

Saves Mobile Data

Visitors on mobile data plans pay for every megabyte they download. Smaller images mean lower data costs for your users and a better experience on slow connections.

Reduces Storage Costs

If you host images on a CDN or cloud storage, you pay for what you store. Compressing before upload directly reduces your storage bill, especially at scale.

Fits Email and Messaging Limits

Email attachments are often capped at 10–25MB. Messaging apps resize images automatically (and often poorly). Compress first so your images arrive exactly as you intended.

Meets Platform Upload Limits

Social media platforms, e-commerce sites, and job portals all have upload size limits. Compressing images lets you get under those limits without cropping or downscaling.

Quick Start

How to Compress Your Images

Drop, adjust, download — done in seconds

1

Drop or Select Images

Drag image files onto the upload area or click to open the file picker. You can add multiple images at once. JPEG, PNG, and WebP files are all supported.

💡 You can drop a whole folder's worth of images at once if your browser supports it. The tool processes them all with the same settings.

2

Adjust Quality and Format

Use the quality slider to control how much compression is applied. Start at 80% — most photos look great at this level with 50–70% size savings. Choose JPEG, WebP, or PNG as your output format.

💡 WebP at 80% quality is typically 30% smaller than JPEG at the same quality. If your target platform supports WebP, it's the best choice for photos.

3

Review and Download

Each image shows original size, compressed size, and the percentage saved. Download individual images or click Download All to get everything in a ZIP file.

💡 If the compression looks too aggressive on a specific image, try raising the quality slider and re-compressing. Your original files are always kept intact.

Features

Everything in One Image Tool

Built for web developers, designers, and anyone who posts images online

Real Compression

Uses the browser's native Canvas API to genuinely compress image data — not just rename a file. JPEG and WebP quality is adjustable from 10% to 95%.

Batch Processing

Drop or select multiple images at once. Every image gets compressed with the same settings, and you can see the results for each one individually.

Quality Slider

A live quality slider lets you control the trade-off between file size and image sharpness. Most images look great at 70–80% quality with 40–70% size savings.

Before / After Comparison

Each compressed image shows the original size, new size, and percentage saved so you can evaluate the result at a glance before downloading.

Format Conversion

Change the output format as part of compression — convert PNG to JPEG, JPEG to WebP, or any combination that gives you the smallest file for your use case.

Completely Private

Your images are compressed using JavaScript in your browser tab. Nothing is uploaded to any server, stored, or logged. Fully safe for personal and confidential images.

Download All as ZIP

Download every compressed image at once in a single ZIP file, or grab individual images one by one. The ZIP is assembled in your browser — no server involved.

Works on Any Device

Fully responsive — works on desktop, tablet, and mobile. Compatible with Chrome, Firefox, Safari, and Edge. No plugins or extensions required.

Use Cases

Who Compresses Images?

From web developers to social media managers — everyone needs smaller images

Web Dev

Website & Blog Images

Compress product photos, hero images, blog post thumbnails, and gallery images before uploading to your website. Faster pages rank better and keep visitors from bouncing.

Hero image: 2.4MB → 180KB (92% reduction) — still looks great

E-commerce

Product Photography

Compress product images for Shopify, WooCommerce, or Etsy. Faster product pages increase conversions — studies show a 1-second improvement in load time increases conversions by up to 7%.

Product photo: 1.8MB → 140KB — Shopify page loads 3x faster

Social Media

Social Media & Content

Compress images before uploading to Instagram, LinkedIn, or Twitter to avoid platform auto-compression, which often produces worse results than doing it yourself first.

Profile banner: 900KB → 85KB — platform quality preserved

Email

Email Attachments

Compress images for email newsletters or attachments. Smaller embedded images mean faster email load times and better inbox placement with spam filters.

Newsletter images: 5 photos × 1.2MB → 5 × 90KB total

Development

App & UI Assets

Optimise app screenshots, UI icons, and marketing assets for app store listings, landing pages, and documentation. Every KB saved improves perceived performance.

App screenshot bundle: 12MB → 900KB — App Store compliant

Business

Reports & Presentations

Compress images before inserting them into PowerPoint, Word, or PDF documents. Smaller images mean smaller file sizes for the whole document — easier to email and share.

Presentation: 45MB with images → 4MB after compressing all images

Format Guide

Which Output Format Should You Choose?

A practical guide to picking the right format for your use case

JPEG

Best forPhotos, complex images

Avoid forLogos, text, transparent backgrounds

MethodLossy

Browser supportUniversal

Use JPEG for any photographic content. At quality 70–85% the compression artefacts are invisible in normal viewing and the file size reduction is significant.

WebP

Best forWeb images of all types

Avoid forLegacy systems requiring JPEG/PNG

MethodLossy or lossless

Browser supportAll modern browsers

WebP is the best choice for new web projects. It produces smaller files than JPEG or PNG at equivalent quality. All modern browsers support it.

PNG

Best forLogos, icons, UI, transparency

Avoid forLarge photographs (use JPEG instead)

MethodLossless

Browser supportUniversal

Use PNG when you need transparency or pixel-perfect graphics. The compression here is structure-level only — colours and edges stay perfect.

Complete Guide

The Complete Guide to Image Compression for the Web

Why Image Compression Is the Single Biggest Win for Web Performance

If you're looking for one thing to do to make your website faster, image compression is it. Images typically account for 50–70% of a typical webpage's total weight. A page full of unoptimised photos from a smartphone can easily exceed 10MB — taking 5–10 seconds to load on a 4G connection. The same page with properly compressed images might load in under 1 second. That difference isn't just about user experience, though that matters too. Google's Core Web Vitals specifically measure Largest Contentful Paint (LCP), which is almost always an image. Compressing your images is the fastest way to improve your LCP score, which directly affects your search ranking.

Understanding Image File Sizes: Why Are Photos So Big?

A photo from a modern smartphone is typically 4–10MB. That's because the camera stores the full sensor data — thousands of pixels of colour information captured at high resolution. A 12-megapixel photo has 12 million individual pixels, each with red, green, and blue values. Uncompressed, that would be about 36MB. JPEG compression gets it down to 3–5MB, but that's still large for the web. The compression algorithms used by cameras are optimised for image quality, not web delivery. Re-compressing specifically for screen viewing, at screen-appropriate resolutions and quality levels, can reduce files to 200–500KB with no visible difference on a monitor or phone screen.

JPEG vs WebP vs PNG: Choosing the Right Format

JPEG is the default for photos and has been since the 1990s. It handles colour-rich photographic content well and is universally supported. WebP is the modern alternative — created by Google and supported by all browsers since 2021. At the same quality setting, WebP files are typically 25–35% smaller than JPEG. For new web projects, WebP is the better choice. PNG is the format for graphics, logos, icons, and anything with transparency. It uses lossless compression, meaning no visual data is removed. Switching a photo from PNG to JPEG or WebP typically saves 70–90% of the file size. Using PNG for photos is one of the most common image optimisation mistakes.

What Quality Level Should You Use?

The 'quality' setting in JPEG and WebP compression controls how aggressively detail is discarded. At 100% quality, very little is discarded and the file is nearly as large as uncompressed. At 50% quality, significant detail is removed and artefacts become visible. The sweet spot for most web use is 75–80% quality. At this level, a trained eye looking at a blown-up comparison can sometimes spot differences, but in normal browsing the images look the same. For print-quality images you plan to zoom into, use 85–90%. For thumbnails, previews, and background images, 60–70% is fine. The most important thing is to test and compare — our before/after display makes this easy.

Image Compression for SEO and Core Web Vitals

Since 2021, Google has used Core Web Vitals as ranking signals. Largest Contentful Paint (LCP) measures how quickly the biggest visible element on the page loads — and that element is almost always an image (a hero photo, a product image, or a banner). Google's target LCP is under 2.5 seconds. On a page with unoptimised images, this is often 4–8 seconds. Compressing your images is the most direct way to improve LCP. Beyond LCP, compressed images also improve Total Blocking Time (TBT) because the browser has less data to parse, and they improve your PageSpeed Insights score directly. Google's guidance on image optimisation specifically recommends using modern formats like WebP and compressing to the minimum quality that maintains visual acceptability.

FAQ

Frequently Asked Questions

Everything you want to know about compressing images

At the default quality setting of 80%, most images look visually identical to the original when viewed on screen. The compression removes data that the human eye has trouble perceiving — mostly subtle colour gradations in areas of low contrast. At very aggressive settings (below 50%) you'll start to see JPEG artefacts, especially around hard edges and text. The quality slider lets you find the sweet spot for each image. The before/after size display helps you judge whether the trade-off is worth it.

More Tools

Related Image & File Tools

More free tools for working with images and files

PDF to JPGFree

Convert every page of a PDF to a high-quality JPG image. Great for extracting slides or document pages as images before compressing them.

Color PickerFree

Pick exact colours from your brand palette using HEX, RGB, and HSL codes — useful when preparing image assets.

Compress PDFFree

Reduce PDF file sizes by up to 90%. Use after compressing the images inside your PDFs for maximum size reduction.

Word CounterFree

Count words, characters, and reading time in your alt text and image captions for SEO optimisation.

Merge PDFFree

Combine multiple PDF files into one. Pairs well with this tool when building image-heavy PDF reports.

Meta Tag GeneratorFree

Generate SEO meta tags including Open Graph image tags for your compressed web images.

Start Compressing Your Images

Free, instant, and 100% private. No account, no uploads, no watermarks.

Compress Images Now Browse All Tools

Image Compressor — Free Online Tool