Why this exists, how it works locally, and why your security is guaranteed.
Here is the honest truth. At my day job, our corporate security proxies and strict firewall guidelines block almost every useful cloud utility. If I need to compile some scanned paperwork or convert images, I am blocked. Want to buy a basic PDF utility with a corporate card? Good luck getting budget approval for a monthly subscription when you only use it twice a week.
After running into these corporate walls far too many times, I decided to take matters into my own hands. I didn't want to upload sensitive tax documents or business proposals to unknown web servers just to merge them. So, I started building the exact utilities I needed myself, focusing on absolute security and zero recurring fees.
The core philosophy of PlanckConvert is simple: **Your files should never leave your device.** Traditional online converters upload your documents to their remote datacenters, convert them, and store them temporarily. This introduces severe vulnerabilities of data caches leaking or files being intercepted.
To eliminate this risk, PlanckConvert operates entirely via client-side processing. When you select a document or a photo, the browser loads the binary data into your local memory sandbox. Advanced web libraries decode and merge the structures entirely on your CPU. Once the process completes, the file is downloaded directly from your browser memory to your hard drive.
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 an error.
To fix this, I looked for online converters. Most of them let me convert maybe three files before slapping me with intrusive pop-up ads. Even worse, the sites I found required me to upload my receipt images directly to their remote servers.
But here's the thing: with a bit of Javascript, you can decode and convert image containers entirely in your local browser memory. Your files never need to leave your device. I wasn't about to feed my personal and company financial receipts to some random web server while dodging spammy ads.
Sure, you can ask a modern AI tool to convert files for you, but wasting valuable API credits or paid subscriptions just to convert a receipt photo felt ridiculous. That’s why I built this local HEIC converter directly into PlanckConvert.
PDF is the absolute standard for business records. When merging, you might sometimes require specific compliance like PDF/A format parameters for long-term archiving.
PlanckConvert handles PDF assembly by restructuring document catalog page streams object-by-object inside the browser, preserving fonts, layers, and interactive forms without stripping security flags unless requested. It is clean, reliable, and completely free.