#DHSeaDev — Desktop Tool — Python · PySide6 · Local-First
PDF Tools
PDF Tools is a Windows desktop utility that clears the small repetitive file jobs out of a document-heavy office. It appends a standing reference PDF to a whole batch of files one drag at a time, and moves hundreds of files between folders from a pasted list of numbers. Everything runs locally, on the files already on the machine, with no service in the middle.
Field Guide
Most document work is not hard. It is small, frequent and interruptive: append the cover sheet, move the batch, fix the names. Each one takes seconds, sits in the middle of work that actually needs judgment, and breaks the thread every time. PDF Tools exists to collapse each of those jobs into a single gesture, and to put a guardrail on the one step in each that cannot be undone.
It is a two-tab window. No settings screen, no profiles, no onboarding, no account. It opens where the work is and closes when the work is done.
What it does
Merge onto a reference
Pick one reference PDF, then drag files onto the drop zone. Each file comes back with the reference pages appended, keeping its own name and folder. No export dialog, no Save As, no destination to choose.
Guarded overwrite
Writing in place is what makes it one gesture, so every drop raises a confirmation naming both files and defaulting to No. Non-PDF input is refused, and the drop zone locks while a write is in progress so a second file cannot race the first.
Move in bulk by number
Paste a list of file numbers, choose a source and a destination, and every file whose name starts with one of those numbers moves across. The list is de-duplicated on the way in, and an identical source and destination is refused outright.
Honest reporting
A bulk move reports moved, skipped and failed as three separate counts, naming the failures and their reasons. A file already present at the destination is skipped rather than clobbered.
What it saves
The figures below are operator estimates from routine daily use, not instrumented measurements, and they describe one office’s workload rather than a benchmark.
- MergeAbout 20 seconds saved per file. At roughly 15 documents on a typical day, that is about five minutes.
- RenameAbout 20 minutes saved per 100 files. At 300 to 500 files on a typical day, that is roughly one to one and three quarter hours.
- Per dayAround one to one and three quarter hours returned in total, previously spent dragging thumbnails and retyping names.
The point is not only the total. It is that none of that time required a decision, and all of it interrupted work that did.
Why it was built
It was written for a legal-support office where the same handful of file operations ran dozens of times a day against expensive general-purpose software that did them at general-purpose speed. Nobody escalates a fifteen-second task, which is exactly why it never gets fixed and why it quietly costs a working week a year.
The engineering is not in the happy path. Appending pages to a PDF is trivial. The work is in what happens when the file is locked, when the dropped file is not a PDF, when the destination already holds that name, or when someone drops a second file while the first is still being written.
Read more
The reasoning behind all three tools, and the case for building the unglamorous ones at all, is written up in The fifteen-second problem. The larger version of the same instinct is ServeBoard. A later write-up, measuring the wrong thing, covers four bugs found while folding these tools into one application.
Privacy
PDF Tools makes no network calls of any kind. There is no account, no telemetry, no update check and no upload. It reads and writes only the files and folders you point it at, on the machine it is installed on. Nothing is sent to DHSeaDev or to anyone else.