I didn't set out to build a suite of engineering tools. I set out to merge two PDFs, for free, without creating an account or getting a watermark stamped across the result.
That's it. Two files, one document. A task so simple it shouldn't have taken more than thirty seconds.
Except every option I found wanted something first. iLovePDF wanted an account. Smallpdf wanted an account, or a subscription if I wanted more than a couple of merges a day. A few tools would merge PDFs for free with no signup, but stamped a watermark across every page for the privilege. One asked me to install a desktop app for a job that should live entirely in a browser tab.
None of this is exotic software. Merging PDFs without an account, a watermark, or a paywall is a solved problem, has been for years. And yet the actual experience of doing it, for free, without handing over an email address or getting a logo slapped across my document, was worse than it had any right to be.
So I decided to just build it myself: a PDF merge tool with no account required and no watermark, period.
I started poking around with Gemini Antigravity, since it was free and I wanted to see how far a weekend project could get without spending anything. It got me far enough to see the shape of what was possible, and far enough to know I wanted more headroom than the free tier gave me.
That's what pushed me to a Claude subscription. Not because I had a grand plan for a whole site, but because I had one small, specific, annoying problem, and I wanted to actually finish solving it instead of leaving it half-built.
Twenty years spent automating engineering data workflows means I know exactly which parts of a "simple" file task are actually simple, and which ones just get treated that way by tools that don't respect your time. Merging two PDFs is squarely in the first category. AI just meant I could build the fix myself over a weekend instead of waiting for someone else to.
Merging PDFs turned out to be the easy part once I sat down to do it properly. The harder question was what to do next, because once you've built one tool that removes a real piece of daily friction, you start noticing all the other small tasks that have the same problem: technically simple, held hostage by accounts, watermarks, or paywalls that don't match how small the actual task is.
That one merge tool became the first tool on toolsbyhari.com, a site built on the same rule: no account required, no watermark on the output, nothing retained after your file is processed. Every tool since has followed it, if the task is genuinely simple, the tool should be too.
Since then the site has grown into things closer to where I started professionally, an ISO 286 fit and tolerance lookup, an involute gear generator, and most recently a PDF redaction tool that actually removes sensitive content instead of drawing a black box over it. Different tools, same premise: build the thing you couldn't find, and don't make people pay for it with their inbox or their document's appearance. The full set of tools is free to use, no account required for any of them.
If you've ever searched for a free PDF merge tool, no account, no watermark, and bounced off every single result, that's the exact frustration this site exists to fix.
Merge your PDFs at toolsbyhari.com/tools/pdf-tools.