How to Compress a JPG to 100 KB for Forms and Portals
The form says 100 KB maximum and your photo is several megabytes. You can fix it in a minute, but there is a trap in how target-size compression works, and a smarter order of steps for big photos.
Switch to Target file size, enter a number in KB and download the compressed copy.
Get a JPG to about 100 KB
- Open Compress JPG and add the photo with Select JPG Images.
- Under Compression mode choose Target file size.
- Enter 90, not 100, and keep the unit on KB. The reason is explained below.
- Press Compress Images, then read the size in the file list.
- Press Download Image. The file is saved as
yourphoto-compressed.jpg.
Why aim at 90 when the limit is 100
Target mode does not stop at the first result under the limit. It tries a quality halfway between 10% and 100%, then tries higher or lower, up to ten attempts, and keeps whichever attempt came closest to the number you typed. Closest can mean slightly above. If a form rejects anything over 100 KB, a result of 101 KB fails. Typing a target 5 to 10 percent lower leaves a safety margin. Always read the size in the file list before you upload.
Also remember the unit. Many forms mean 1 KB = 1,024 bytes, and some count 1,000. Aiming at 90 KB covers both.
When quality alone is not enough
The search cannot go below quality 10%, and a result near that floor looks poor anyway. The cause is nearly always too many pixels. A 4000 x 3000 phone photo has 12 million of them, and squeezing that into 100 KB leaves almost nothing for each pixel. The better route is to reduce the dimensions first, then compress:
- Open Resize Image, choose Pixels and keep Aspect ratio on Locked.
- Set a width that suits the use, for example 800 or 1000 pixels for a form photo.
- Download the result, then run it through Compress JPG in Target file size mode.
A 1000 x 750 picture has 750,000 pixels, about one sixteenth of the original. It can reach 100 KB at a much higher quality setting than the full-size file could. That is an illustration of the idea, and the exact figures vary with the image.
Forms that also fix the dimensions
Passport, exam and job portals often ask for both a size cap and exact dimensions, for example 200 x 230 pixels or 35 x 45 mm. Compression keeps the width and height unchanged. Decide the dimensions first, then the file size. A sensible order is: crop to the right shape with Crop Image, resize to the required pixels, then compress. Working out a ratio such as 35:45 is easier with the aspect ratio calculator, and cropping to exact pixels shows the crop step in detail.
Which kinds of photo shrink well
| Photo type | Behaviour |
|---|---|
| Face against a plain background | Compresses well; flat areas cost few bytes |
| Scene full of leaves, fabric or text | Fine texture eats the budget; resize more |
| Scanned document saved as JPG | Text edges show artifacts quickly; keep dimensions larger and quality higher, or use PDF |
| Screenshot | Often better as PNG, but forms asking for JPG force the choice |
A worked sequence for a typical phone photo
Suppose your phone photo is 4032 x 3024 pixels and about 3.5 MB, and the portal wants a JPG under 100 KB. Compressing it directly in Target file size mode will force a very low quality and the face may look blotchy. Instead, resize to a width of 1000 pixels with the aspect ratio locked, which gives 1000 x 750, and compress that file to a 90 KB target. The result usually looks acceptable at normal viewing size, because the portal will display it small anyway. The numbers here are an example, not a measurement of your file, so judge by looking at the output at the size the portal will show it.
Open the final file once more before uploading. Check that the face is clear, that nothing important has been cut off, and that the size is below the limit in the file properties of your computer, which is the figure the portal will see.
What changes in the file
- Width and height stay as they were.
- Camera and location tags are not kept, because the image is redrawn. More in removing EXIF data.
- Each pass is lossy, so always compress from your original, not from an earlier compressed copy.
If it still will not go under 100 KB
- Resize smaller. Halving the width removes three quarters of the pixels.
- Try WebP only if the portal accepts it: JPG to WebP. Many government forms accept JPG only.
- Check the broader checklist in shrinking images to fit an upload limit, and compare other targets in compressing JPG to different sizes.
Everything runs in your browser. A photo of your ID or passport is not uploaded when you compress it with this page, and for several files the ZIP is built locally with JSZip, loaded from a CDN.
Frequently Asked Questions
Will the result always be under 100 KB?
Not guaranteed. The tool keeps the attempt closest to your target within ten tries, so enter about 90 KB if the limit is 100 KB and check the size shown.
Why does a large photo look bad at 100 KB?
Too many pixels share too few bytes. Resize to the dimensions you need first, then compress.
Does compression change the width and height?
No. Dimensions stay the same. Use Resize Image or Crop Image when the form needs exact pixels.
Is it safe to compress an ID or passport photo here?
The image is processed in your browser and is not uploaded by this tool.
Can I compress several photos at once?
Yes. Add many files and download compressed-images.zip. The target size applies to each image.
What name does the output file have?
The original name followed by -compressed.jpg.