Stop uploading your sensitive data: I built a privacy-first Developer Suite (JSON, PDF, Base64)

Published: (December 12, 2025 at 07:00 AM EST)
2 min read
Source: Dev.to

Source: Dev.to

The Problem

We have all been there: you need to format a messy JSON response, decode a Base64 string, or merge two PDF files quickly. A quick Google search often leads to:

  • Pop‑up ads and newsletter modals.
  • “Wait 15 seconds to download.”
  • Privacy anxiety: Are they storing my PDF contract? Is my API key in this JSON being logged?

Simple utility tools shouldn’t be this complicated, slow, or intrusive.

Solution

I built Har​isLab.tech – a free, privacy‑focused collection of developer tools and converters. The goal is straightforward: no ads, no tracking, and no data retention.

Architecture

Text‑Based Tools

For utilities such as JSON Formatter, Base64 Encoder, Password Generator, and Regex Tester, all processing happens entirely in the browser. The data never leaves the DOM, making the tools lightning‑fast and 100 % secure—you could even disconnect from the internet and they would still work.

Heavy Tasks (PDF / Image)

For more resource‑intensive operations like PDF merging or image conversion (WebP/JPG), a PHP backend is used with a strict Ephemeral Processing policy:

  1. Upload – File is temporarily stored in a restricted tmp folder.
  2. Process – The script performs the conversion/merge.
  3. Deleteunlink() is called immediately after the response is generated.
  4. No Logs – Filenames, metadata, and user IPs are never stored.

Tools Overview

  • PDF Tools – Merge, Split, and a new Page Resizer (supports A0, A1, A2, A3, A4).
  • Image Tools – Batch Convert (WebP/PNG/JPG) and Compress.
  • Dev Utilities – JSON Validator, XML‑YAML Converter.
  • Security – SHA/MD5 Hash Generator, Bcrypt Generator.

I have built 50+ tools; the above are the ones I find most useful for daily development work.

Future Plans

I am continuously optimizing performance and adding new utilities. The next major step is moving more image processing to WebAssembly (Wasm) to eliminate server dependency entirely.

Live Demo

https://harislab.tech

Happy coding! 🚀

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