Frequently asked questions
Does “exact size” mean exactly that many bytes?
No. A successful output is at or below the selected byte ceiling. The encoder searches for a fitting result; it does not add padding to make the number exact.
What is the difference between KB and KiB?
A decimal KB is 1000 bytes; a KiB is 1024 bytes. The binary checkbox selects which multiplier the target uses. The tool shows exact target and output byte counts.
Can it meet a minimum file size?
It does not pad files to meet a minimum. If your destination gives a range, check the lower bound as well as the upper limit.
Will my image keep its dimensions?
Not necessarily. Large images are resized for practical processing and the selected target. A dimension preset may impose an additional cap. Check both output sides.
What changes when I choose another target?
Existing results are cleared so they cannot be mistaken for the new settings. Select Compress again to process the original files with the new target.
Are my images uploaded?
Image processing runs in your browser. The site downloads page assets and may load its HEIC decoder or ZIP library when needed; those requests are separate from selected image contents. See the privacy policy for hosting and contact details.
Is the tool fully offline?
Features whose code has already loaded may work offline. First-use HEIC conversion or ZIP may require a download. Do not assume all features are cached after opening the homepage.
What metadata is kept?
The tool re-encodes pixel data rather than copying the original EXIF block. It does not offer metadata preservation. An image can still identify a person or location visually, so metadata removal is not anonymization.
What happens to transparent areas?
JPG cannot preserve transparency, so its output uses a white background. PNG and WebP output can retain transparent pixels.
Does a size preset make a valid application photo?
No. Presets set byte and maximum-dimension choices only. Verify the current official instructions, composition, format, minimum dimensions and any other rules.
Why did HEIC conversion fail?
The browser decoder may not support that particular file. Keep the original and export a JPEG through a compatible image application, then try that file.
Can I compress a PDF or animation?
This tool handles supported still image files, not PDF documents. It does not preserve animation, Live Photo motion or depth information.
What are the current limits?
Up to 30 files per batch, each at most 40 MiB (41,943,040 bytes). Custom targets must be whole numbers from 5 to 5120. Processing speed and available memory depend on your device.