Free, private, no sign up
JPG to KB Converter
Convert any JPG to the exact KB size you need, from 10KB to 500KB or more. Set a minimum too when a form asks for a range like 20KB to 50KB. Everything runs in your browser, so your photos never leave your device.
or drag and drop them here
Built for JPG and JPEG files. PNG, WebP, GIF, BMP, and AVIF also work and come out as JPEG. Paste with Ctrl+V on a computer. Up to 30 images at once.
More options
- Private by designCompression runs on your device. Nothing uploads to a server.
- Stays a real JPEGFinds the highest JPEG quality that fits your limit and shows the quality your photo started at.
- Free with no watermarkNo account, no daily limit, and no logo on your photos.
How to convert JPG to KB
- Add your JPG. Tap Select JPEG images, drag a photo into the box, or paste it with Ctrl+V. You can add up to 30 images at once.
- Choose a target size. The tool selects 100KB by default. Pick another preset, or choose Custom and type any size. If the form gives a range, type its lowest value as the minimum.
- Download your JPG. The tool finds the highest quality that fits under your limit, usually within a few seconds. Then tap Download to save it.
What Is the JPG to KB Converter?
This tool converts a JPG photo to the exact file size you need, measured in KB. Pick 10KB, 20KB, 50KB, 100KB, or type any number. The tool then finds the highest quality that fits under that number.
It also handles something most size tools ignore: a minimum. Many forms ask for a range, such as a photo between 20KB and 50KB. Type the lower number as the minimum, and the tool makes sure your file lands inside the range.
Everything runs inside your browser. Your photo, signature, or ID scan never uploads to our server.
MB, KB, and bytes in plain words
A phone photo is usually a few megabytes (MB). Forms ask for kilobytes (KB), which are much smaller. In the system most computers use, 1 MB is 1,024 KB, and 1 KB is 1,024 bytes. Some websites count 1 KB as exactly 1,000 bytes instead, which matches the decimal kilo described by the National Institute of Standards and Technology. So converting a 3MB photo to 50KB means making it about 60 times smaller.
How to Convert JPG to KB
The steps stay the same on every device.
On a phone
- Open this page in Chrome on Android or Safari on iPhone.
- Tap the size you need, such as 50 KB, or tap Custom and type a number.
- Tap Select JPEG images and pick your photo.
- Wait for the Done message, then tap Download.
On a computer
- Pick your size first, or choose Custom and type any size in KB or MB.
- Drag your JPG into the box, click Select JPEG images, or paste it with Ctrl+V.
- Click Download, or Download all if you added several photos.
When the form gives a range
Say the form wants a photo between 20KB and 50KB. Choose 50 KB as the maximum. Then type 20 in Minimum size in KB. The tool keeps the file at 50KB or less and makes sure it is at least 20KB.
What Each KB Size Gets You
KB is file size, so the same KB number can hold different pixel sizes. To show realistic results, we converted one grainy 3,000 × 2,000 photo of 2,903,118 bytes to every preset:
| Target | Result | Pixel size | JPEG quality |
|---|---|---|---|
| 10 KB | 9,153 bytes | 606 × 404 px | 67% |
| 20 KB | 19,549 bytes | 900 × 600 px | 51% |
| 30 KB | 28,604 bytes | 900 × 600 px | 62% |
| 50 KB | 47,619 bytes | 900 × 600 px | 76% |
| 100 KB | 92,947 bytes | 978 × 652 px | 84% |
| 200 KB | 187,369 bytes | 1,384 × 922 px | 79% |
Two things stand out. First, small targets mostly cost pixels, not just quality. Second, from 20KB to 50KB the photo kept the same 900 × 600 pixels while its quality rose from 51% to 76%. We used heavy grain on purpose because it is the hardest detail to compress, so ordinary photos usually keep more pixels at the same size.
Features of the Tool
- Any size in KB. Presets for 10KB, 20KB, 30KB, 50KB, 100KB, 200KB, and 500KB, plus any custom size in KB or MB.
- Minimum size. Set a lower limit for forms that ask for a range.
- Safe for every portal. On by default, it keeps the file under the limit whether a site counts 1KB as 1,000 or 1,024 bytes.
- Original quality check. Each result shows the JPEG quality your photo started at.
- .jpg or .jpeg. Choose the extension your form expects under More options.
- Batch mode. Convert up to 30 photos at once.
- Before and after view. Tap Compare to check the result.
- No upload, no account, no watermark.
How the Minimum KB Option Works
Shrinking a file is easy. Growing one without changing the picture is not, because a JPEG cannot gain detail it never had. So when your result is smaller than the minimum, the tool adds a block of blank text inside the file.
That block uses the comment marker, a part of the format defined in the JPEG standard, ITU T.81. Image viewers show only the picture, so the photo looks exactly the same. The file simply weighs more.
We tested this with a 4,914 byte photo and a 20KB to 50KB range. The tool produced a 20,544 byte file, just above the 20,480 bytes that 20KB means in the stricter count. The file still opened as a normal 400 × 300 JPEG.
The tool counts the minimum with 1,024 bytes per KB and adds a small margin, so the file passes a minimum check whichever way the site counts. If you type a minimum that is not smaller than the maximum, the tool tells you instead of guessing.
How the Tool Hits Your KB Size
- It checks whether work is needed. If your JPG already fits under the limit, the tool keeps the original file.
- It searches for the best quality. At full size, it tests JPEG quality between 50% and 92% and keeps the highest one that fits.
- It reduces pixels only when needed. If even 50% quality is too large, the tool works out how much smaller the photo must be and tries again. For very small results, under 200 pixels on a side, it may go below 50% quality.
- It applies your minimum last. If the finished file is below your minimum, it adds the blank comment block described above.
Why not just lower the quality to fit? JPEG works on 8 by 8 blocks of pixels, and as Google’s web.dev guide to JPEG explains, pushing compression too far makes those blocks visible. A slightly smaller photo at healthy quality looks cleaner than a large photo full of blocks.
Why Choose This Tool
- It handles ranges. Many size tools only stop at a maximum. This one also respects a minimum.
- It hits the number the form checks. Safe for every portal covers both ways websites count KB.
- It never wastes quality. When your file already fits, you get the original back with zero added loss.
- It shows what you start with. The original quality readout tells you whether a soft result comes from the tool or from the photo itself.
- Your photo stays with you. Nothing leaves your device, which matters for ID photos and signatures.
Who Should Use This Tool
- Exam and job applicants whose forms give a KB limit or a KB range for a photo or signature.
- Students uploading documents to admission portals.
- Office staff sending ID photos to HR or government systems.
- Anyone emailing photos where a small attachment size matters.
- Website owners who want images below a fixed KB budget.
Tips for the Best Result
- Use the largest size the form allows. If the range is 20KB to 50KB, choose 50KB, not 20KB.
- Crop first. A tight crop around the face or the signature leaves more bytes for the detail that matters.
- Start from the original photo. A copy forwarded through a chat app has already lost quality.
- Resize when the form also gives pixels. If the form names exact dimensions, use our image resizer, which sets pixels and KB together.
- Check the result. Tap Compare and look at the eyes, the text, or the signature lines before you upload.
Fixes for Common Problems
The portal says my file is too large
Keep Safe for every portal on. It aims a little below your limit, so the file passes whether the site counts 1KB as 1,000 or 1,024 bytes.
The portal says my file is too small
Type the form’s lowest value in Minimum size in KB. The tool will add blank data until the file is large enough, without changing the picture.
The photo looks blurry at 10KB or 20KB
Very small limits leave little room for detail. Crop tightly first, and check whether the form allows a larger size. If it also gives pixel dimensions, match those exactly with the resizer, because fewer pixels make each one sharper.
The form rejects .jpeg or .jpg
Open More options and change File extension. The image data stays the same.
My iPhone photo will not open
Your photo is probably HEIC. Try this page in Safari, which usually opens HEIC photos, or set your camera to Most Compatible so it saves JPEG.
Why You Can Trust This Tool
This tool runs entirely in your browser. Your photos never travel to our server, and we cannot see them. You can check this yourself. Load this page, switch off your internet, and convert a photo. The tool keeps working.
We test every tool on this site with real files before we publish a guide about it. Read our Privacy Policy, Disclaimer, and how we write and test our guides for the full picture.
Real Test Results
Besides the size guide above, we tested the range feature and the error checks on the live tool.
| Test | Original | Result |
|---|---|---|
| Small 400 × 300 JPG, range 20KB to 50KB | 4,914 bytes | 20,544 bytes, picture unchanged, opens normally |
| 3,000 × 2,000 JPG at 90%, range 20KB to 50KB | 3,674,091 bytes | 48,549 bytes at 900 × 600 px, quality 69%, no padding needed |
| Minimum 60KB with a 50KB maximum | Any photo | Clear message that the minimum must be smaller than the maximum |
Every result stayed under its safe maximum, and the tool made no network requests while it worked.
Share Your Result
Did your photo pass the form’s check? Tell us in the comments below. Mention the form, the KB range it asked for, and the final size. Real results help the next person get it right the first time.
Frequently Asked Questions
How do I convert a JPG to KB for free?
Pick the size you need at the top of this page, add your JPG, and wait for Done. Then tap Download. There is no sign up and no watermark.
How do I convert a JPG to 20KB?
Tap 20 KB and add your photo. The tool finds the best quality that fits and reduces pixels if it must. For a clearer result, crop the photo tightly first.
How do I make a photo between 20KB and 50KB?
Choose 50 KB as the maximum and type 20 in Minimum size in KB. The tool keeps the file inside that range.
Can I compress a JPG to under 100KB?
Yes. Tap 100 KB. In our test, a 2.9MB photo came out at 92,947 bytes and 978 × 652 pixels.
How many KB are in 1 MB?
In the system most computers use, 1 MB is 1,024 KB. Some websites use 1,000 instead. Safe for every portal keeps you under the limit either way.
Will converting to fewer KB reduce quality?
Yes, a little, because JPEG is a lossy format. The tool keeps the loss as small as possible by choosing the highest quality that fits.
Does adding a minimum size change my photo?
No. The tool adds a block of blank text inside the file. The picture stays exactly the same, and the file opens normally.
Can I convert PNG or WebP to KB here?
Yes. PNG, WebP, GIF, BMP, and AVIF files work too, and the tool saves them as JPG.
Can I convert many photos at once?
Yes. Add up to 30 photos, and Download all saves them one after another.
Is it safe to convert my ID photo here?
Yes. The tool works inside your browser, so your photo never uploads to a server. You can confirm it by switching off your internet after the page loads.