I Built 15 Free Browser Tools That Never Touch a Server

Description and use

Napizo is a set of 15 free browser tools that run entirely client‑side, eliminating server costs and privacy concerns.

Problem

Free online tools often require uploading files to a server, incurring costs and raising privacy concerns.

Outcome

Napizo delivers 15 free browser tools that process files locally, reducing costs, improving privacy, and simplifying deployment on static hosts.

Workflow

• 1. User selects a file in the browser.
• 2. JavaScript libraries (pdf.js, pdf-lib, Canvas API, Web Workers, Tesseract.js, ag-psd) process the file locally.
• 3. Result is generated and offered for download or display.
• 4. No data is sent to any server.

Evidence

your files never leave your device.

Source

Running everything in the browser flips the economics: the user's device does the work, so there is no per-file server cost at all.

Source

A phone browser will kill your tab if you load a 100-page PDF into RAM carelessly. The fix: process pages in chunks, release object URLs promptly, and never keep the full decoded document in memory longer than necessary.

Source