Diagram Tool
A diagram editor that runs entirely inside your web browser, from a folder on your own computer. One page: what it does, what it does not do, and exactly what leaves the machine.
The job it does
An AI assistant — Claude, Gemini, Grok, Copilot, any of them — drafts an architecture diagram and hands it over as whatever it can produce: an HTML page, an SVG, a PDF, a draw.io file, a screenshot. Open it here. Every box, line and label becomes editable; fix the wording, swap in the official vendor icons, re-route the arrows, in minutes rather than redrawing. Then save in whatever the next person needs — PDF for the review packet, PNG or JPG or a real PowerPoint slide, Word for the document, Visio for the colleague in Visio, Mermaid for a ticket, DXF for a CAD shop, draw.io for the colleague who lives in diagrams.net. The PDF, Visio, PowerPoint, Mermaid and DXF files you save re-open here fully editable, so the round trip never dead-ends.
What it is
| Opens | PDF, SVG, HTML pages with an SVG inside, Word (.docx) with a picture, Visio (.vsdx), PowerPoint (.pptx), draw.io, Mermaid (.mmd), DXF, PNG / JPG screenshots, and its own Project files. |
|---|---|
| Makes editable | Boxes, lines with arrowheads (they stay attached when boxes move), text, icons, groups. Screenshots are recognised as best it can (text by OCR, shapes by image analysis) with the original kept underneath. |
| Icon libraries | Official AWS, Azure and Google Cloud architecture icons, plus Microsoft Entra, C4 model stencils and other vendor marks, bundled. Any PDF or folder of SVGs you own can be added as a library. |
| Saves | PDF, Visio, PowerPoint, Mermaid and DXF (all re-open here fully editable — the editable diagram travels inside the file), SVG, PNG, JPG, Word, draw.io, Project. |
| Runs on | Microsoft Edge or Chrome, from index.html. No install, no admin rights, no account, no licence key, no server. |
What it isn't
| Not a cloud service | There is no sign-in, no sharing link, no sync. Files are ordinary files on your disk or network share; you share them the way you share any file. |
|---|---|
| Not a Visio replacement for everything | It is built for architecture and flow diagrams: boxes, connectors, icons, labels. It does not do org charts with data binding, Gantt charts, or floor plans to scale. |
| Not perfect on pictures | A PDF, SVG or draw.io file comes in exactly. A screenshot is a guess — good enough to fix by hand, not a conversion. |
What leaves your computer
Nothing. The page carries a Content-Security-Policy that forbids connections to any address except data it already holds. Opening a file, recognising a screenshot (OCR runs locally, in the browser), saving, and the icon libraries all happen on the machine. An automated test opens the tool, imports every sample, saves in every format, and fails if a single network request is made.
| Your diagrams | Never sent anywhere. They stay in the browser's memory while open and in the file you save. |
|---|---|
| Telemetry / analytics | None. No usage data is collected. |
| Updates | Only when someone replaces the folder. The tool never checks for or downloads anything. |
| Support, privacy, terms | Links in the About dialog (and on this page) open appsupport.pro in your browser when you click them. That is a navigation you start; the tool itself still makes no network request. |
| Fonts, icons, libraries | Bundled in the folder (pdf.js, JSZip, OpenCV.js, Tesseract OCR and the English model, vendor icon sets). Nothing is fetched at run time. |
| Browser storage | Which panels you collapsed, whether the Library pane was open, and one optional developer flag in local storage. No documents, no history, no cookies. |
How to check this yourself
Open index.html, press F12, choose the Network tab, then open a diagram, edit it and save it. The list stays empty apart from the tool's own files loading from file://. Or disconnect from the network entirely: the tool works the same.