Start around 80% quality
Choose a local photo, generate a JPEG at the initial setting, and compare the reported size with your input. Lower quality usually produces a smaller file but can soften texture or add block-like artifacts. The slider is an encoder setting, not a promised percentage of size savings.
Keep dimensions, change encoding
This tool retains the image’s pixel dimensions and exports JPEG. Transparent regions become white. Use the resizer first if the dimensions themselves are too large, or the converter when you need to preserve transparency.
Inspect the actual downloaded copy
The on-page preview is the original, not a simulated compression preview. Open the downloaded JPEG and zoom in on fine text, faces and sharp edges. A file can become larger when it was already efficiently compressed; the result message explicitly reports this. No exact target file size is guaranteed.
Local processing, with clear limits
These are standalone website utilities, separate from the CalcLock iPhone vault. Selecting a photo does not import it into the app. The tool’s code processes selected images in your browser and does not upload them, use a remote image service or save them to browser storage. Downloaded files go wherever your browser normally saves downloads.
Re-encoding creates a new pixel-based copy without copying the original EXIF metadata. This applies only to the generated copy, not your original, backups or other shared copies. It is not a promise that every identifying detail has been removed: visible content can identify you, and browsers may add encoding information. Color rendering and orientation may differ between applications; inspect your output.
Inputs are limited to 25 MB, 24 million pixels and 10,000 pixels on either side. Some devices may run out of memory below these limits. Only browser-decodable PNG, JPEG and WebP files are accepted. Animated images are flattened to a browser-decoded frame; do not use this tool to preserve animation. Clear releases the tool’s image references and download URLs; it does not securely erase device memory or remove downloaded files.
More photo utilities
All planning and photo tools · Understand the vault’s privacy boundaries