An AI Diagram Maker for the Assistant You Already Use

Free
No sign-up
Works offline

Ask ChatGPT or Claude for a flow in text, paste it in, and watch it become a narrated, animated diagram — free, in your browser, no sign-up.

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Present reveals your diagram one step at a time, on its own.

AI RAG pipeline — the finished diagram this player draws step by step — This compact player stays quiet while you read. Open the full presentation when you want narration and the complete walkthrough.

Diagramium is a free, browser-based AI diagram maker in three honest senses: it draws diagrams from AI-written text (ask ChatGPT or Claude for a flow as sequence lines and paste them in), it ships a gallery of narrated animated explainers about AI topics, and it gives every diagram an AI voice that presents it step by step. What it does not do is generate a diagram from a prompt by itself — it is the drawing half of a partnership with the assistant you already use.

The live example on this page is one of those gallery diagrams presenting itself on loop: shapes reveal in order and a spotlight follows the current step; present it yourself and an AI voice reads each step with word-by-word subtitles. All of it runs in your browser — nothing to install, no sign-up to draw, present, or export stills, and your diagram content is never uploaded.

Paste AI-written text, get a living diagram

Sequence diagrams in Diagramium can be typed as plain text, and that single fact turns any AI assistant into a diagramming partner. A line like Browser->Server: add item to cart becomes two lifelines and an arrow the moment it lands in the sequence editor — ask your assistant to describe a system in that form, paste the reply, and the whole flow draws itself.

The division of labor is honest: the assistant is good at recalling how a system works, and the editor is good at drawing it. After the paste everything is a normal diagram — drag participants, recolor messages, add activation bars, fragments, and notes with full visual editing.

Prompts you can copy, and what comes back

You do not need prompt engineering — you need one sentence that names the flow and the format. Paste any of these into ChatGPT or Claude as written:

"Write an e-commerce checkout as lines of the form A->B: message, one line per step, no other text."
"Describe an OAuth login with Google as sequence lines like Client->AuthServer: message."
"Turn the incident timeline below into sequence-diagram lines, one message per line."

The checkout prompt comes back as text like this:

Shopper->Store: place order
Store->Payments: charge card
Payments->Store: payment confirmed
Store->Shopper: send receipt

And the OAuth prompt like this:

Client->AuthServer: redirect to sign-in
AuthServer->User: show consent screen
User->AuthServer: approve access
AuthServer->Client: return auth code

The assistant writes that text; Diagramium draws it. Paste the reply into the editor and the lifelines, arrows, and layout are already in place.

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Animated explainers about AI, ready to edit

Ready-made animated explainers about AI live in the Explore gallery: how RAG works, what an AI agent is, how an LLM answers a question, what MCP does, and how agent memory fits together. Each is a narrated, step-by-step presentation, and each is fully editable — open one in the gallery, reword a step, swap the hand-drawn Doodle look for a professional palette, and present the result as your own.

That cuts both ways: finished diagrams about AI for a lecture or a team briefing, and starting points for a version in your own words.

Where your data goes: nowhere

AI workflows usually raise the question of where your content ends up; here the answer is short: the diagram never leaves your device. Text you paste becomes a local document — no feature transmits diagram content to a server, and once the app is open in a tab it runs without a connection. There are no ads and no third-party analytics; the only telemetry is a set of anonymous per-diagram counters.

Narration is the one optional cloud touch, and even there the default voices run on your device — the spoken track can stay as local as the drawing. The gallery's AI explainers play locally too, narration included.

AI voice narration performs your notes

AI voice narration is the third pillar: you write a short note per step, and a voice performs it while the diagram reveals. Subtitles follow with word-by-word highlighting, a spotlight tracks the current shape, background music is optional, and each step can carry a "why this matters" insight — the sentence a good presenter adds after the facts.

If drafting notes is the slow part, ask your assistant for one sentence per step and paste those in too. When the presentation is ready, you can record a live take as you run it.

From assistant reply to playing diagram

From an AI chat window to a diagram playing on a website:

Open the sequence editor in your browser — no install, no account.
Give ChatGPT or Claude one of the prompts above, or your own flow described the same way.
Paste the reply. Lifelines, arrows, and layout appear at once.
Refine by hand: drag participants, add alt or loop fragments, recolor, and add per-shape animation such as pulse or glow.
Write — or paste — a one-line note per step so the narration has something to say.
Press Present to watch the run, then export: PNG or SVG right away, or animated GIF, video, and animated SVG with a free account.
To put a moving diagram on your own site: any published gallery diagram embeds as a self-playing iframe — here is the walkthrough.

Frequently asked questions

Is Diagramium free, and what does an account add?

Diagramium is free. Drawing, presenting, and still exports (PNG and SVG) need no account at all. A free account adds the animated export formats — GIF, video, and animated SVG — and syncs your favorites and likes in the gallery. There is no paid tier.

Does Diagramium generate diagrams from an AI prompt?

No. There is no built-in prompt-to-diagram generator. Instead, you ask an assistant you already use — ChatGPT or Claude — to write a flow as sequence text lines, and Diagramium draws that text as a diagram. Editing, styling, and narration then happen visually in the editor.

Which file formats can I export?

PNG and SVG stills are available to everyone, with no account. Signing up for a free account opens the moving formats: animated GIF, video, and animated SVG. Recording a live take of a presentation as it plays needs no account either.

Where are my diagrams stored, and does it work offline?

Diagrams are stored locally — in your browser's own storage and in any files you download. No feature transmits diagram content to a server, and after the app has loaded, losing the connection does not stop you from drawing or presenting.

Which AI topics does the explainer gallery cover?

The Explore gallery includes narrated, animated explainers on how RAG works, what an AI agent is, how an LLM answers a question, what MCP does, and how agent memory fits together — alongside science and engineering topics. Every explainer is editable, so you can reword one before presenting it.

Can I embed a self-playing AI diagram on my website?

Yes. Any published diagram from the Explore gallery can be embedded in another site as an iframe that plays on its own: the diagram reveals step by step in the visitor's browser, with no plugin and no extra script required. A short walkthrough on the Diagramium blog covers the embed code and its options.

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