How do I reduce image size to an exact KB limit (like 20 KB or 50 KB)?

Traditional percentage sliders force endless trial-and-error. PressZero uses a dual-axis binary search bisection algorithm: you enter your target kilobyte limit (for example 50 KB for UPSC or 20 KB for NTA), and the in-memory engine calculates the exact quantization matrix in under 25ms to hit within ±2% of that ceiling.

Are my uploaded photos or signatures saved on any server?

No. PressZero is 100% client-side. All processing occurs inside your web browser via HTML5 Canvas, WebAssembly, and Web Workers. Exactly zero bytes are uploaded to any server or database.

How does the signature bleach filter work?

When you take a picture of a paper signature with a smartphone, phone shadows and yellow ambient lighting cause portal rejection. PressZero's adaptive bleach filter computes ITU-R BT.601 pixel luminance, wiping shadows to pure #FFFFFF white while boosting pen ink contrast.

Can I use PressZero as an offline image reducer?

Yes. You can install PressZero as a Progressive Web App (PWA) directly from your browser, or download our standalone native executables: PressZero-Setup.exe for Windows or PressZero.app for macOS. Both work completely disconnected from the internet in full air-gap mode.

Which government exam and visa portals are supported?

PressZero has pre-calibrated presets for UPSC Civil Services, NTA NEET/JEE/UGC-NET, SSC Staff Selection Commission, US Visa DS-160 (600x600 px under 240 KB), Schengen Biometric Visas (35x45 mm), and Indian Passport Seva.

Core Engine

System Architecture & Security Model

PressZero operates entirely in-memory on the client machine with zero network transmission.

+-------------------------------------------------------------+
| USER DEVICE (Browser or Standalone Desktop App)             |
|                                                             |
| [ File Input ] ---> [ HTML5 Canvas ]                        |
|                            |                                |
|                            v                                |
|                 [ Web Worker Thread Pool ]                  |
|                 |- Binary Search Bisection (O(log n))       |
|                 |- Adaptive Luma Bleach Filter              |
|                 |- EXIF / Geolocation Scrubber              |
|                            |                                |
|                            v                                |
|                 [ In-Memory Blob / ZIP Export ]             |
|                            |                                |
|                            v                                |
|                 [ Local Instant Download ]                  |
+-------------------------------------------------------------+
                             |
                             X (0 Bytes Transmitted)
                             v
               [ Remote Backend Servers ]

Network Egress Verification

You can independently verify zero network transmission: open Developer Tools (F12 or ⌥⌘I), switch to the Network tab, and perform a compression. Exactly 0 outgoing HTTP requests are made.