ToolKoala Blog

Engineering notes on browser-based privacy tools.

• How to Verify a Web Tool Never Uploads Your Files (DevTools Walkthrough)

  2026-05-30

  Don't trust "we don't store your files" — verify it. A 60-second DevTools check that shows whether a web tool uploads your file or processes it entirely in your browser.

• How We Got a 100-Tool React App to a 307 KB Main Bundle (From 6 MB)

  2026-05-25

  ToolKoala ships over 100 file-processing tools in a single React + Vite app. The main bundle started at 6 MB. We got it to 307 KB — a 95% reduction — by fixing six specific things. Here's exactly what they were, in order of impact.

• OCR in 2026 — Tesseract vs Google Vision vs ChatGPT vs Apple Live Text (Real Accuracy Numbers)

  2026-05-22

  I tested 4 OCR tools on 100 real-world images — receipts, screenshots, handwriting, multi-language docs, low-light photos. Here are the actual character accuracy numbers, not the marketing claims.

• How to Save a PDF as JPG — 4 Methods Tested (Without Adobe Acrobat)

  2026-05-22

  Adobe Acrobat is $20/month. Here are 4 free ways to save a PDF as a JPG image — Preview, Word, online services, and browser tools — tested with real PDFs, with quality comparisons and file size numbers.

• Remove Background from Images in 2026 — Honest Comparison of Photoshop, Canva, GIMP, and Free Browser Tools

  2026-05-22

  I tested 6 tools on 30 images — product photos, portraits, hair, fur, glass. Here's which one actually wins, where each fails, and why the answer depends on what you're shooting.

• How We Built a Video Compressor That Never Uploads Your File

  2026-05-20

  Most "online video compressors" send your file to a server. Here's how we built one that runs 100% in your browser using FFmpeg.wasm — and how you can verify it yourself in 10 seconds.