About the Image Compressor & Converter
Most “free” image compressors upload your photo to someone else’s server. This one downloads the encoders instead — the same WebAssembly builds of MozJPEG, libwebp, libavif and OxiPNG that power Google’s Squoosh — and runs them in a background thread in your browser. Your image is decoded, resized and re-encoded without ever leaving the tab.
You don’t have to take that on trust. Below every result the page lists each network request made since you added the image: the only ones are one-time downloads of encoder code from jsDelivr. Once they have loaded you can go offline and keep converting. The finished file is also scanned byte by byte for EXIF, GPS, XMP, IPTC and colour-profile blocks, so “metadata removed” is a checked result rather than a promise.
Pick a format, drag the quality slider and watch the size change, then compare the two versions with the split-screen divider. The codecs are the reference implementations, so results match what you would get from the command-line tools at the same settings. HEIC photos can only be opened in browsers that can decode them (Safari).
Encode this image in all four formats at the current quality and size, and see which one actually wins for this picture — the answer differs between photos, screenshots and logos.
Need it under a limit — an upload form, an email, a page-weight budget? Enter the size and the tool searches for the highest quality that fits, encoding for real at each step.
Generate every width in every format you choose, download them as one zip, and copy
ready-to-paste <picture> markup with srcset, sizes, width and height.
Choose or drop several images at once. Each is processed with the settings above, one after another in the background thread, and the results download together as a single zip.
How to Use the Image Compressor & Converter
Drop an image on the page, choose it from your device or paste it from the clipboard. It is converted immediately with the default settings — WebP at quality 75 — and every change you make to the format, the quality slider or the maximum size re-encodes it within a second or two. The first time you pick a format, its encoder (between about 150 KB and 1.2 MB of WebAssembly) downloads once; after that it is cached by your browser. Drag the divider across the preview to compare the two versions, then download.
Choosing a Format
| Format | Best for | Transparency | Browser support |
|---|---|---|---|
| AVIF | Photographs where every kilobyte counts; typically the smallest file | Yes | Chrome 85+, Firefox 93+, Safari 16+ |
| WebP | The all-rounder: photos and graphics, fast to encode | Yes | Every current browser |
| JPEG | Maximum compatibility: email, old software, print services | No — becomes white | Universal |
| PNG | Screenshots, logos, line art that must stay pixel-exact | Yes | Universal |
The JPEG encoder here is MozJPEG, which produces files roughly 10% smaller than a standard JPEG library at the same quality number by using trellis quantisation and progressive scans. PNG output goes through OxiPNG, which tries different filter and compression strategies and keeps the smallest lossless result — it never changes a pixel, so it cannot shrink a photograph much.
What the Quality Number Means
Quality is not a percentage of anything. It is an encoder-specific dial controlling how aggressively fine detail is discarded, and the same number means different things in different formats: AVIF at 50 looks roughly like WebP or JPEG at 75–80. File size falls steeply at first and then flattens, which is why dropping from 95 to 80 often halves a file with no visible change, while going from 60 to 40 saves little and starts to show. The damage appears first in fine texture — hair, grass, fabric — and as ringing around sharp edges and text, so judge the result on those areas, not on sky.
Resizing Beats Compressing
A modern phone photo is 4,000 pixels or more across; a blog column is rarely wider than 800. Serving the full
image and letting the browser shrink it wastes about 95% of the bytes before compression even starts. Set a
maximum width equal to the largest size the image will ever be displayed at — doubled for sharp high-density
screens — and you will usually save more than any quality setting can. For pages that must look sharp on
both phones and 4K monitors, generate several widths and let the browser choose with srcset.
Metadata: What Your Photos Say About You
A photo straight from a phone typically carries an EXIF block with the camera model, lens, exposure settings, the exact time it was taken and, unless location was switched off, the GPS coordinates to within a few metres. Many cameras also record a serial number. Post a photo of your front garden with that intact and you have published your address. Stripping is on by default here, and the Metadata Check panel shows what the original carried and what the new file contains, read from the file’s own bytes. Colour profiles are removed as well: the pixels are converted to standard sRGB first, which is what the web assumes.
How “Nothing Is Uploaded” Works
Your image is read with the browser’s own file API, decoded to pixels on a canvas and handed to a Web Worker
running the encoder compiled to WebAssembly. The encoded bytes come back to the page and become a download link
created in memory. At no point is there a request that carries the image — which is exactly what the network
panel under each result lets you check, alongside your browser’s developer tools. The encoders are fetched
from jsDelivr at pinned versions of the open-source @jsquash packages.
Making a QR code for the page the image is going on? The QR Code Generator exports PNG and SVG. Checking how the rest of a site is built? Try the Website Tech Stack Detector, or browse every Dev & Tech tool.
Frequently Asked Questions
Which is better for the web, WebP or AVIF?
AVIF usually produces the smallest files at the same visual quality, often 20 to 30 percent smaller than WebP for photographs, but it is slower to encode and was supported later: Safari only added it in version 16. WebP is supported by every current browser and encodes quickly. The safe production answer is both, served with a picture element: AVIF first, WebP second, JPEG as the fallback.
What quality setting should I use?
For photographs, a quality of 70 to 80 in WebP or JPEG and about 50 to 60 in AVIF is visually indistinguishable from the original for most people while cutting file size by half or more. Graphics with flat colour and sharp text compress better as PNG or as WebP at high quality. Use the before and after divider at full zoom on the busiest part of the picture, such as foliage, hair or text, because that is where compression shows first.
Is it safe to compress private photos with an online tool?
It depends on where the work happens. Many compressors upload your file to their server. This one does not: the encoders are downloaded as code and run inside your browser tab, and the page lists every network request made after you add an image so you can see that none of them carries it. You can also disconnect from the internet once the encoder has loaded and it keeps working.
Does converting an image remove its EXIF data and GPS location?
Here it does by default. The image is decoded to raw pixels and re-encoded, and the new file is written without EXIF, XMP, IPTC or colour-profile blocks. The page then scans the finished file byte by byte and lists every block it contains, so the claim is checked rather than assumed. If you want to keep the camera EXIF, untick Strip metadata; that works for JPEG output and keeps any GPS coordinates too.
Why did my PNG get bigger when I converted it?
PNG is lossless, so its size depends on how compressible the pixels are, not on a quality setting. A photograph saved as PNG is enormous by nature; converting it to WebP or JPEG will shrink it dramatically. A PNG that was already optimised may barely change, and converting a small, already compressed JPEG to PNG makes it larger, because PNG has to store every pixel exactly. The result card says so when the output is larger than the input.
