Compress an image to 500 KB
Reduce a photo to under 500 KB with almost no visible loss — the usual ceiling for email attachments, forum posts and marketplace listings.
- Runs in your browser
- Files are never uploaded
- Free, no account
1 KB = 1024 bytes, the same arithmetic your operating system uses.
Only kicks in when quality 5 still overshoots.
500 KB: small enough to send, big enough to look right
At half a megabyte most 12-megapixel phone photos land somewhere in the quality 82–90 band — above the threshold where compression artefacts become visible at normal viewing size. That makes 500 KB the practical ceiling for things you send to other people: email attachments, forum and marketplace listings, insurance claims, estate agent uploads and support tickets.
Email attachment arithmetic
Mail servers apply their limit to the encoded message, not to your files. Attachments are base64-encoded in transit, which adds roughly 33%, and there is the message body and headers on top. So a “25 MB limit” is really about 18 MB of actual files:
| Mail limit | Usable payload | Photos at 500 KB |
|---|---|---|
| 10 MB (many corporate gateways) | ≈ 7.5 MB | 15 |
| 20 MB (Outlook / Microsoft 365) | ≈ 15 MB | 30 |
| 25 MB (Gmail) | ≈ 18 MB | 36 |
| 50 MB | ≈ 37 MB | 74 |
Note that the recipient's limit applies too, and it is usually the smaller of the two. When in doubt, split a large set across two messages rather than discovering it bounced.
Will 500 KB hurt the photo?
Rarely at normal sizes. Where it shows is in three specific places: smooth gradients such as a clear sky can develop faint banding; hard high-contrast edges can pick up a thin halo; and fine repeating texture — fabric weave, foliage, gravel — softens first. If your image is mostly one of those, expand the search table in the result and check which quality the tool settled on. If it is above 85, you have nothing to worry about.
Keeping full resolution
At a 500 KB target the quality search almost always succeeds on its own, so the pixel dimensions are left exactly as they were. If you want to guarantee that, switch off “Shrink if quality is not enough” — you will then get the smallest file the quality search could manage, plus an explicit warning if it could not reach the target. That matters for insurance and claims photos, where cropping or resizing can undermine the evidence.
Sending many photos at once
Drop the whole set in. Each photo is searched independently to 500 KB, and “Download all as .zip” produces one archive to attach — which also stops mail clients re-compressing or re-orienting your images on the way out. There is no cap on how many you process, because the work happens on your machine rather than in someone's job queue.
Privacy matters for this size of file too
500 KB uploads are typically holiday photos, house interiors, damaged vehicles, injuries and documents — the exact material people are least comfortable handing to a free web service that “deletes files after one hour”. Nothing here is uploaded at all: the decode, the search and the encode all run in this tab. As a side effect, the exported file has no EXIF, so it no longer carries the GPS coordinates of your home.
Other targets
200 KB · 1 MB · 100 KB · any target you type.
Questions
Will 500 KB visibly damage my photo?
Rarely. Most 12-megapixel phone photos land in the 82–90 quality band at 500 KB, which is above the threshold where artefacts become visible at normal viewing size.
How many photos fit in a 25 MB email?
About 45 at 500 KB each — and mail servers count the base64 encoding overhead, which adds roughly a third, so budget for around 35 to be safe.
Is WebP safe to email?
Modern mail clients display it, but some older desktop clients and print shops still do not. For an attachment someone else will open, JPG remains the safer choice; for your own website, WebP wins.
Can I keep the original dimensions?
Yes — switch off “Shrink if quality is not enough”. At a 500 KB target the quality search almost always succeeds on its own, so resizing rarely gets triggered anyway.