What 500 KB is good for
A photo straight from a phone camera is usually 2–6 MB, far more than a screen needs to show it well. At 500 KB it takes a fraction of the space and, at normal viewing size on a phone or laptop, usually looks the same. That makes it a sensible size for:
- Email. Personal Gmail accounts allow 25 MB of attachments per message in total, and anything larger is replaced with a Google Drive link (Gmail Help). At up to 500 KB per photo, 30 photos come to no more than 15 MB, comfortably inside that limit.
- Chat and shared albums. Smaller files send faster on mobile data and take less space on phones.
- Website galleries and portfolios: large, sharp images on pages where the photo is the point, such as an event gallery, a property listing or a portfolio.
- Upload fields with a 500 KB cap. Some application and registration forms allow up to 500 KB for supporting images. Check each field, because the photo, signature and document fields often have different limits.
How the tool reaches 500 KB
The compressor doesn't apply one fixed setting to every photo. For each file it works through these steps and stops at the first one that fits:
- Save the photo at full size and 92% quality. Smaller photos often fit here, and the line under the file shows Quality 92%.
- Search for the highest quality between 92% and 35% that keeps the photo at full size and under 500 KB.
- If even 35% is too large, reduce the dimensions, then search the quality again at the new size. The line shows Dimensions reduced to fit 500 KB together with the new pixel size.
35% is the floor because JPG photos below roughly that quality start to break up into visible blocks. Past that point, losing some pixels looks better than losing more quality.
One exception: a photo that's already under 500 KB, already in the output format and not narrowed by Limit width is left exactly as it is, and the line says the original was kept. Change any setting and every photo in the list is processed again with the new settings, so you can try a different limit without adding the files again.
What to expect from different photos
The result depends mostly on how many pixels a photo has and how much fine detail is in the scene. As a rough guide:
| Photo | Likely result at 500 KB |
|---|---|
| Already 2000 px wide or less, such as a downloaded or forwarded image | Usually fits with dimensions unchanged and a good quality setting |
| 12 MP phone photo of a simple scene: a document, a wall, a clear sky | May fit at full size, with the quality lowered |
| 12 MP phone photo full of detail: trees, crowds, gravel, patterned fabric | Usually reduced in dimensions as well as quality |
| Photo from a 48 or 50 MP camera mode | Dimensions reduced; choosing a width yourself gives a cleaner result |
| Screenshot or graphic saved as PNG | Stays PNG, with colours reduced if needed so text and edges stay crisp |
If the result line shows a low quality figure and you'd prefer a cleaner picture, turn on Limit width and choose the width yourself, for example 2000 px. Fewer pixels at a higher quality usually look better than many pixels at a low one, especially in skies and skin tones.
iPhone HEIC photos
iPhones save photos as HEIC when the camera format is set to High Efficiency, which is the default. Many websites, forms and Windows PCs don't handle HEIC well, so the compressor converts it to JPG in the same step: with the output left on Same, a HEIC photo comes out as a JPG of up to 500 KB.
- Safari 17 and later, on iPhone, iPad or Mac, opens HEIC directly.
- Other browsers, including Chrome on Windows and Android, use a converter built into the page. It runs on your device like the rest of the tool, but a large HEIC photo can take a few seconds longer than a JPG.
- No thumbnail at first? The original HEIC isn't previewed, so the thumbnail appears once the JPG is ready.
- If a photo won't open, export that photo from the Photos app as a JPG, or switch the iPhone camera's format to Most Compatible so new photos are saved as JPG. The HEIC to JPG page shows where that setting is.
If you need a JPG at full quality rather than 500 KB, use that converter instead.
Worked example: an event gallery for a website
You've taken 20 photos at a school event on an iPhone and want to add them to a gallery on the school website. Each is a 12 MP HEIC file, and you'd like every image under 500 KB so the gallery opens quickly on parents' phones.
- Add all 20 photos. They're converted to JPG along the way.
- Turn on Limit width and enter 2000. Portrait photos come out taller than landscape ones, since only the width is limited.
- If your website accepts WebP, switch the output to WebP for a little more detail in the same 500 KB. Leave it on Same, which gives JPG for these photos, if you're not sure.
- Press Download all (20) and upload the images from the ZIP. The whole set comes to no more than 10 MB, a fraction of what the originals take up.
Since the compressing happens on your own device, the only place the pupils' photos are uploaded to is the school's own site. And because each HEIC is saved again as a new JPG, the location your phone recorded in the originals isn't carried over.
When to resize instead of compress
Compressing sets the file size and lets the tool decide the pixels. Sometimes it's the pixels you really need to control:
- The destination shows images at a known size. If a site displays photos 1200 px wide, there's no benefit in sending 4000 px. Set Limit width to 1200 here, or use the Image Resizer for exact dimensions, and the file may end up well under 500 KB.
- A form asks for exact pixels, such as 1200 × 800. The Image Resizer crops or fits the photo to that size and can apply a 500 KB limit at the same time.
- You might compress again later. Every JPG save loses a little detail. Keep your originals and compress from them, not from an earlier compressed copy.
- You need a PDF. Build it from the compressed photos in JPG to PDF. For a PDF you already have, go to compress PDF to 500KB.