The quickest way: set a target size
Lowering the quality slider by guesswork takes several tries. A target size does the work for you: you type the limit, and the tool finds the best quality that still fits under it.
- Open the free Tolket Image Compressor.
- Drop in your photo or scan. JPG, PNG and WebP all work, and you can add several files at once.
- Under Target size in KB, tap 20 KB, 50 KB, 100 KB, 200 KB or 500 KB, or type any number your form asks for.
- Click Compress images. The new size appears next to each file; download it and upload it to your form.
Everything runs inside your browser, so your photo, ID or signature is never uploaded to our server. That matters for personal documents.
Shortcuts: compress to 20KB · 50KB · 100KB · 200KB.
Why forms ask for such small files
Application systems receive thousands of uploads a day, so they cap file sizes to save storage and keep pages fast on slow connections. A passport-size photo only needs a few hundred pixels on screen, which is why limits such as 50KB are common. A phone photo, by contrast, is often 3–6 MB: up to a hundred times larger than the form allows.
What decides the file size
Three things control how many kilobytes an image takes:
- Dimensions: the number of pixels. Halving both the width and the height leaves a quarter of the pixels, which usually cuts the file size by well over half.
- Quality: JPEG and WebP throw away detail you are unlikely to notice. Quality around 60–80% is a good balance; below about 40% blocky artefacts start to appear.
- Format: JPEG suits photos and is accepted almost everywhere. WebP is smaller at the same quality but some older forms reject it. PNG is lossless and usually much bigger for photos.
Our compressor first tries to reach your target with quality alone. If even a modest quality is still too large, it reduces the dimensions step by step, because a slightly smaller, clean image looks better than a full-size, blocky one.
Step-by-step for the most common limits
Signature under 20KB
- Sign in dark ink on plain white paper and photograph or scan it in good light.
- Use the Image Cropper to crop tightly around the signature; empty paper adds kilobytes.
- Compress with a 20 KB target. A signature with a clean white background usually fits easily.
Passport-size photo under 50KB
- Check the required ratio or pixel size on the form, for example a square photo or 35 × 45 mm.
- Crop to that ratio with the Image Cropper. If exact pixels are required, set them in the Image Resizer.
- Compress with a 50 KB target and save as JPEG.
Document photo or certificate under 100KB–200KB
- Scan or photograph the page flat, filling the frame, with no shadows.
- Crop the edges, then compress with a 100 KB or 200 KB target. For text-heavy pages WebP keeps letters sharper if the form accepts it.
- If the form wants a PDF instead, convert the result with the Image to PDF Converter.
Fixing common upload errors
| Error message | What it means | Fix |
|---|---|---|
| File too large | The image is over the maximum size. | Set the exact limit as your target size, or a few KB lower to be safe. |
| File too small | Some forms also have a minimum, such as 10KB. | Use a higher target, for example 40 KB instead of 15 KB. |
| Invalid file type | The form only accepts JPG or JPEG. | Choose JPEG as the output format before compressing. |
| Wrong dimensions | The width or height in pixels is outside the allowed range. | Resize to the exact pixels first, then compress. |
| Photo looks blurry | The target is very small for a large, detailed photo. | Crop away background and resize to around 600 px wide before compressing. |
iPhone photos are often saved as HEIC, which many forms and browsers cannot read. Switch the camera to Settings › Camera › Formats › Most Compatible so new photos are saved as JPEG.
Tips to keep your image sharp
- Crop before you compress. Every pixel you remove is a pixel you do not have to squeeze.
- Start from the original. Compressing an already compressed JPEG again and again adds artefacts each time.
- Use even light and a plain background. Noise and busy backgrounds take far more space than smooth areas.
- Aim slightly under the limit. Some systems count 1KB as 1,000 bytes instead of 1,024, so a 50 KB target with a little headroom is safer.
How to check an image’s file size
On Windows, right-click the file and choose Properties. On a Mac, select it and press Command + I. On Android or iPhone, open the file in the Files app and view its details. The compressor also shows the original and new size of every file.
Frequently asked questions
Can I compress an image to exactly 20KB?
The tool saves each image just under your target, for example 19.6KB for a 20KB limit, which is what upload forms check for. Exactly 20,480 bytes is rarely possible or needed.
Does compressing a photo reduce its quality?
Slightly, but at sensible settings the difference is hard to see on screen. Very small targets for large photos are the exception; crop and resize first for the best result.
Can I do this on my phone?
Yes. The Image Compressor works in mobile browsers on Android and iPhone, with no app to install and no sign-up.
Is it safe to compress ID photos and documents online?
With Tolket the processing happens on your own device, so your files are not uploaded. Always download the result and keep your original as a backup.