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Private by design
Images are compressed with your browser's Canvas API. No upload, no server, no tracking of your files.
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Batch & fast
Drop dozens of photos at once. Three images are processed in parallel using your own CPU.
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Convert & resize
Switch between JPEG, PNG and WebP and cap the longest side at 1920 px (or any size) in one pass.
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Before/after slider
Compare original and compressed pixels side by side before you download anything.
How to compress an image online with Squish
- Add images. Drag and drop files onto the drop zone, click "browse files", or paste a screenshot directly from your clipboard.
- Pick your settings. Leave quality at 75 for a great balance, choose an output format (or keep the original), and optionally resize large photos to 1920 px.
- Check the results. Each file shows the old and new size, the percentage saved and the final dimensions. Click a row to open the before/after comparison slider.
- Download. Save files individually or hit "Download all". Pro users can grab everything as a single ZIP.
Why compress images?
Images are the heaviest part of almost every web page, email and chat message. A single photo straight from a modern phone is 3–6 MB and 4000+ pixels wide, far more than any screen can display. Compressing it to 200–400 KB makes a measurable difference:
- Page speed and Core Web Vitals. Largest Contentful Paint (LCP) is usually a hero image. Smaller images load faster, improve your Google ranking signals and reduce bounce rate, especially on mobile connections.
- Email attachment limits. Gmail and Outlook cap attachments at 20–25 MB. Compressing a dozen photos lets you send them in one message instead of five.
- Storage and bandwidth. Smaller files mean cheaper hosting, faster backups and more room on your phone or cloud drive.
- Upload limits. Forums, CMS plugins, marketplaces and job portals often reject files above 1–2 MB. A compressed image sails through.
JPEG vs PNG vs WebP: which format should you use?
JPEG (JPG)
The universal choice for photographs and anything with smooth gradients. JPEG is lossy: it throws away detail your eye is unlikely to notice. It does not support transparency. Use it when compatibility matters most (email, older software, printing services).
PNG
Lossless and supports transparency, which makes it ideal for logos, icons, screenshots with text and UI mockups. PNG photos are huge, though, often 5–10× larger than the same image as JPEG. If your PNG is a photo, convert it to JPEG or WebP.
WebP
Google's modern format combines the best of both: lossy or lossless, with transparency, and typically 25–35% smaller than JPEG at equal visual quality. Every current browser supports WebP, so it is the best choice for websites. Some desktop apps and social networks still prefer JPEG, so keep that in mind for uploads elsewhere.
Which quality setting should I pick?
The quality slider (10–100) controls how aggressively JPEG and WebP discard detail. Perceived quality is not linear: going from 100 to 85 cuts file size roughly in half while looking identical at normal viewing distance; dropping below 60 starts to show blocky artifacts around edges and in skies.
- 85–90: portfolio photography, print previews, product zoom images.
- 75–85 (sweet spot): blog posts, e-commerce listings, social media, email. This is Squish's default.
- 60–70: thumbnails, background images, previews where speed matters more than fidelity.
- Below 50: only when you must hit a strict size limit. Pro's target file size mode finds the highest quality that fits automatically.
Lossless vs lossy compression
Lossless compression (PNG, WebP lossless) rearranges data more efficiently without changing a single pixel. Savings are modest, usually 5–30%, and come mostly from stripping metadata and better encoding. Lossy compression (JPEG, WebP lossy) approximates the image and can shrink files by 70–90%. For photos, lossy at quality 75–85 is almost always the right call; for graphics with sharp edges and flat colors, stick with lossless PNG.
Privacy: your images never leave your device
Most online compressors upload your files to a server, process them there, and keep them for hours or days. That is a problem for family photos, ID scans, medical images, client work and anything under NDA. Squish is different: compression runs entirely in your browser through the HTML5 Canvas API. There is no upload, no account and nothing to delete afterwards. As a bonus, re-encoding through the canvas strips EXIF metadata, including GPS coordinates, camera serial numbers and timestamps, so the photos you share reveal less about you.
Compressing images for the web, Instagram and email
For websites and blogs
Choose WebP, quality 75–80, and resize to 1920 px for full-width hero images or 1200 px for in-article photos. Aim for under 200 KB per image. Keep PNG only for logos and screenshots with text.
For Instagram and social media
Instagram re-compresses everything you upload, so feed it a clean source: JPEG at quality 85, resized to 1080 px wide (the 1080 px preset above). Uploading a smaller, well-compressed file avoids the muddy look Instagram's own compression produces on huge originals.
For email and messaging
JPEG at quality 70–75 and a 1600 px longest side is plenty for viewing on any screen and keeps a 10-photo album under 3 MB total. Recipients see sharp images and your message is not bounced for size.
Frequently asked questions
Is Squish really free?
Yes. Compressing, resizing and converting images is completely free with no sign-up and no watermark. You can process up to 10 images (10 MB each) per batch for free. Squish Pro is an optional one-time upgrade that adds unlimited batches, 50 MB files, ZIP download, target file size mode and custom filenames.
Are my images uploaded to a server?
No. Squish compresses images entirely inside your browser using the Canvas API. Your files never leave your device, nothing is stored, and the tool even works offline once the page has loaded.
Which image formats are supported?
You can compress JPG/JPEG, PNG and WebP, and convert between them. GIF, BMP and SVG files can be opened and re-encoded as PNG, JPEG or WebP. HEIC/HEIF photos from iPhones are not supported by browsers, so export them as JPEG first.
Does compressing reduce image quality?
JPEG and WebP compression is lossy, but at the default quality of 75 the difference is practically invisible while the file is usually 60–80% smaller. PNG output is lossless, so pixels are preserved exactly. Use the before/after slider to check any image before downloading.
What is the maximum file size?
Free users can compress images up to 10 MB each. Squish Pro raises the limit to 50 MB per file. Because processing happens on your device, very large images also depend on your browser's available memory.
Can I compress many images at once?
Yes. Drag and drop a whole folder of images or select multiple files. Squish processes three images in parallel and shows a summary of total space saved. Free batches are limited to 10 images; Pro removes the limit and lets you download everything as a single ZIP.