Under the Hood: The Architecture of Image DPI Calculator
Print DPI is pixels divided by inches, not a cloud “enhance.” Optional image drop uses URL.createObjectURL plus HTMLImageElement.naturalWidth/Height. You type physical size; the tool reports horizontal and vertical DPI. The image never uploads.
Memory Allocation & Browser Threading Mechanics
Object URL is revoked on load. Pixel dimensions are two numbers. Arithmetic is two divisions per render. Decode cost is the browser image pipeline, local.
Algorithmic Deep-Dive: Code Snippet & Logical Analysis
const dpiX = printInchesW > 0 ? pixelsW / printInchesW : 0; const dpiY = printInchesH > 0 ? pixelsH / printInchesH : 0;
This is not reading EXIF XResolution unless you type it. It answers “if I print this many pixels at this size, what PPI do I get?” Zero print size is guarded to avoid Infinity.
The Local Storage Sandbox & Volatile Data Pipelines
File preview may hold an object URL via the preview list. Removing the file drops it. No EXIF write-back.
Verifying True Privacy: How to Audit Your Browser's Network Tab
F12, Network, clear, drop an image. blob: URLs are local. No image POST.