Start with the destination’s requirements
A file-size limit and a pixel-size requirement are different. A 1080 × 1350 image can be either 80 KB or several megabytes depending on its contents, format and quality. Write down the accepted format, required dimensions and maximum bytes before changing anything.
Work through size, format and quality
- Keep the original. Export a separate copy for delivery.
- Resize first if dimensions are specified. Use the image resizer to crop or fit without guessing.
- Choose an accepted format. JPG is useful for photos and legacy upload forms. WebP can preserve transparency. This compressor does not export PNG.
- Enter a maximum size. Open the 100 KB compressor or set your own limit in the general compressor.
- Decide whether dimensions may change. Keep dimension reduction disabled when a form requires exact pixels.
- Inspect the actual result. “Target met” means the output is at or below the selected number of bytes. Inspect fine details before downloading.
A worked setup for a profile photo
Suppose a form asks for a 600 × 600 JPG below 100 KB. Crop a copy to 600 × 600, choose JPG in the compressor, set the maximum to 100 KB, and disable dimension reduction. Start with 85% maximum quality. The tool searches for a quality level that fits; the exact result depends on the image. If it cannot reach the limit, it labels that result clearly. This is an example setup, not a promised compression ratio.
Choose a limit for your task
| Limit | Check before using it |
|---|---|
| 100 KB | Small photos may work well; inspect hair, edges and text carefully. |
| 200 KB | Try this if 100 KB looks soft and your destination allows a larger file. |
| 500 KB | Useful as a starting target for larger images; verify dimensions and visual detail. |
These are workflow examples, not universal platform requirements. SocialSwiss uses decimal KB: 100 KB means 100,000 bytes. A destination using KiB may describe the same file differently.
Common problems
The compressed file is larger
An already efficient original can grow when re-encoded at high quality. Try lower quality, compare WebP if supported by your destination, or keep your smaller original. File conversion alone does not guarantee a reduction.
Text or logos look blurry
Lossy compression can damage fine edges. Increase the target or preserve dimensions. Keep a lossless original for editing and print.
A transparent background becomes white
JPG has no alpha channel. Choose WebP to retain transparency, or use another export workflow if the destination requires PNG.
The upload still rejects the image
Check the format, dimensions and actual byte count. Renaming an extension does not change the format. A form may have additional constraints that compression cannot fix.
A batch is slow
Use fewer or smaller originals. The compressor processes up to 20 images sequentially to reduce peak memory use, then offers one ZIP download. Files stay on your device.
What the tool changes
It decodes the original in your browser and exports a new JPG or WebP. Target mode searches quality and, when enabled, reduces dimensions. It does not preserve all original metadata, and it does not optimize animated images. Browser encoder results vary; always inspect the final file.
Technical references: Canvas image encoding and image format characteristics.