Developer JB's personal diary entries on how and why these utilities were built.
At my job, filing for expense reimbursement requires uploading a receipt showing every single line item. It’s great when you get a digital PDF receipt, but so many places still hand you a physical piece of paper. So I take a photo of the paper receipt with my iPhone, go to upload it to our corporate system, and boom—rejected. It turns out the system only accepts JPEGs, and Apple’s default HEIC format throws a generic error. (Classic corporate software, honestly.)
So I went looking for an online converter. Long story short, it was a nightmare. Most sites let you convert like two files before spamming you with annoying pop-up ads. And the worst part? They wanted me to upload my receipts—with actual company financial data—straight to their shady remote servers.
But here is the catch: you don't even need a server for this. With a tiny bit of Javascript, you can decode and convert image formats right in your browser's local memory. Your files never leave your machine. There was no way in hell I was uploading company financial documents to some sketchy web server while dodging spammy ads.
Sure, you could ask an AI tool to write a script or convert it, but wasting paid API credits or subscriptions just to convert a receipt felt dumb. So I got fed up, stayed up late, and built this local converter right into the toolkit.
We’ve all been there: you need to compile a bunch of reports into a single PDF document for a big presentation. Naturally, I filed a request to get a license for Adobe Acrobat Pro. Two weeks later, procurement shoots it down: "Budget rejected. Use free online tools instead."
Which is absolutely hilarious, because our security team sends weekly warnings stating: "Do NOT upload proprietary company documents to unverified cloud websites." It’s the ultimate corporate catch-22. If I upload the files and there's a leak, I get fired. If I don't merge the files, the project stalls and I get chewed out.
So I said screw it and built my own. I used pdf-lib to write a client-side merging tool that runs entirely in local browser memory. No servers, no network requests, no budget approval needed. It takes your PDFs, combines them locally, and downloads the output in seconds. Take that, budget cuts.
I even added quick tools to rearrange pages or trash irrelevant ones before merging. If you are struggling under corporate budget rules like me, help yourself to this tool.
Whenever a client sends back a modified contract claiming they "just made a few minor edits," my anxiety levels spike. Did they actually just fix typos, or did they quietly alter a critical liability clause? Spotting these changes by staring at printouts side-by-side with a yellow highlighter is absolute eyeball torture.
Copy-pasting confidential contract text into free online diff checkers is a massive security violation. I wasn't about to send NDAd legal documents to some random server. So yeah, I built a local diff engine to stop the madness. It parses DOCX and PDF text, compares them word-by-word inside your browser, and shows additions and deletions side-by-side.
It even spits out a clean HTML diff report you can download and share offline. Now I can verify contract edits in seconds without getting dry eyes or risking a security breach.
Comparing linear document text is relatively simple. Comparing multi-dimensional spreadsheets (Excel) is a complete nightmare. If you insert a single row or column in the middle of a sheet, every cell address below it shifts, causing standard diff engines to flag the entire document as modified.
I'm currently staying up late, tearing my hair out over a custom grid-alignment algorithm. The goal is to filter out all the noise from layout shifts and only flag the cells that actually changed. It's coming soon. If you want to speed up my progress (and your commute home), buy me a coffee—it keeps the builder sane and the code flowing.
IN PRODUCTION