Most photos are done in about a second
Graviton compresses on your own processor, across several cores at once, so there is no upload to wait for and no download to come back. A 24-megapixel photo takes a couple of seconds.
Where the time goes
The slowest part is the part Graviton skips
With an upload-based compressor, every image travels to a server and back. On a slow or mobile connection, that trip can take longer than the compression itself.
| Step | Typical upload-based compressor | Graviton |
|---|---|---|
| Send the image | Upload the whole file to a server | Nothing to send |
| Wait your turn | Depends on how busy the service is | Your device works only on your images |
| Compress | On the service’s servers | On your processor, several images at once |
| Get the result | Download the compressed file | Already on your device |
Skipping the upload is also why your images never leave your device. Speed and privacy come from the same design.
Under the hood
What makes it quick
No upload, no download
Your image is already on your device, and so is the result. Your connection speed doesn’t hold the work up.
Several cores at once
Images are compressed in background Web Workers, several at a time, spreading the work across your processor’s cores while the page stays responsive.
Encoders built for the job
MozJPEG, libwebp, libavif and OxiPNG run in your browser as WebAssembly, the same open-source engines desktop tools use.
Ready before you click
When you add an image, Graviton loads the encoder it needs in the background, so the first compression doesn’t wait for it.
A short search for exact sizes
For an exact file size, Graviton tests a small copy of a large photo first to predict the right quality, so most images settle in a few encodes.
Try new settings right away
Change a setting and compress again straight away. There is nothing to re-upload, and compressing never counts against your daily limit.
What to expect
What affects how long it takes
Graviton doesn’t promise the same time for every image. These are the things that change it.
| Factor | What to expect |
|---|---|
| Image size | Most photos take about a second. A 24-megapixel photo takes a couple of seconds. |
| Output format | AVIF makes the smallest files but takes longer to encode than JPG or WebP, especially for large photos. |
| Goal | An exact file size takes a few encodes instead of one, so it is a little slower than a fixed quality. |
| Your device | Graviton runs more images in parallel on devices with more cores and memory. On older phones, resizing very large photos helps. |
| Batch size | Images in a batch are compressed several at a time where your device allows, so a batch is quicker than doing them one by one. |
Want quicker results for the web? Resize images to the size they will be shown, and convert JPG to WebP for a fast encode and a small file. Smaller images also make your own site faster: see how to optimize images for web performance, and use bulk compression for whole sets.
FAQ
Speed questions
How long does it take to compress an image?
Most photos take about a second. A 24-megapixel photo takes a couple of seconds. AVIF output and exact file sizes take a little longer, because they do more work.
Does my internet speed matter?
Very little. Images are never uploaded or downloaded, so only the page and its encoders need to load, plus a short message that approves each download and, on Free, counts it against your daily limit.
Does Pro compress faster?
No. Everything runs on your own device, so speed is the same on both plans. Pro only removes the daily download limit.
Will compressing slow my computer down?
Graviton uses several processor cores while it works and stops when the batch is done. The work runs in background Web Workers, so the page stays responsive.
Why does AVIF take longer?
AVIF does more work per image to reach smaller files, especially for large photos. If speed matters more than the last few kilobytes, choose WebP.
Tools for this
Tools that make images quick to load as well as quick to compress.
See how fast it is on your device
Drop a photo and time it yourself, no account needed. A free account includes 3 downloads a day.
Try it on a photo