Comparison

DuckViz vs ChatGPT for data analysis: what it actually costs.

ChatGPT is great for explaining a query. It's a bad place to put your customer database. Here's the side-by-side — token cost, data exposure, and what each tool was actually built for.

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Two bills you don't see at signup.

When you paste a CSV into ChatGPT, you pay twice: once in tokens, once in data exposure. The token bill is metered and shows up on your invoice. The data bill arrives later — when legal asks where the customer file went, or when an export ends up indexed in a future model's training set.

DuckViz was built to remove both bills. The AI runs once on column names — never on row values — and the rest of the analysis happens inside your browser tab.

Side by side, on a real spreadsheet.

Same task: a 50MB sales export, ten follow-up questions, one executive summary at the end.

ChatGPT

  • Paste the CSV — but it won't fit; you chunk into 6 parts
  • Each chunk burns ~120k input tokens
  • Every follow-up question resends conversation history
  • Customer rows are now in a third-party log
  • Charts? Screenshot the markdown table into Excel

DuckViz

  • Drop the file — DuckDB-WASM ingests it in your tab
  • AI sees ~30 column headers, picks 5–7 charts
  • Follow-ups run as DuckDB SQL, in-browser, free
  • No row ever leaves your machine
  • One click: a real PDF report with embedded charts

Where the tokens actually go.

Token bills don't scale with how much insight you got — they scale with how much text you sent. Here's why pasted-file workflows get expensive fast:

  • Files don't fit in context — even GPT-4 Turbo's 128k window holds roughly 20MB of CSV. Larger files force chunking, which multiplies your input cost by the number of chunks.
  • Conversation history compounds — every follow-up question typically resends the prior conversation (and often the file) as input. The 10th question can cost 10× what the 1st did.
  • Output tokens are billed too — long markdown tables, generated SQL, written narrative. Pretty output is not free output.
  • DuckViz sends ~30 tokens per dashboard — column names and types, that's it. The same dashboard costs the same one credit whether the underlying file is 4MB or 4GB.

ChatGPT is still the right tool for some jobs.

We're not telling you to cancel your ChatGPT subscription. They're different shapes of tool — pick the one that fits the shape of the problem.

Reach for ChatGPT when

  • You're learning a SQL function or DuckDB syntax
  • You want to brainstorm what to look for in your data
  • The data is a public dataset you'd post on a blog
  • You need a creative writing or general-purpose assistant
  • The dataset fits comfortably in a single message

Reach for DuckViz when

  • The file is real customer, finance, or production data
  • You want to iterate without watching a token meter
  • You need actual interactive charts, not markdown tables
  • You want a board-ready PDF, not a copy-paste exercise
  • Your security team won't approve a file upload

Frequently asked

Can't I just use ChatGPT's Code Interpreter?

You can — and the file does run in a sandboxed Python environment, which is a real privacy improvement. But the file still leaves your machine and lives in OpenAI's infrastructure for the session, and the analysis still consumes tokens whenever the model writes or interprets code. DuckViz runs the analysis on your machine and never uploads the file at all.

Is DuckViz also using OpenAI under the hood?

Yes — for AI features, we send schema metadata (column names, types) to OpenAI to recommend chart types and write SQL. We never send row values. The SQL then executes locally in DuckDB-WASM against your data. The AI never sees the result.

What about my data — really, where does it go?

Nowhere. The file is read inside your browser tab using the File API; DuckDB-WASM ingests it into an in-memory database that lives in the same tab. We persist sessions in IndexedDB on your device. None of this touches our servers. See our privacy policy for the full breakdown.

Can DuckViz do everything ChatGPT can?

No, and it doesn't try to. DuckViz is purpose-built for one workflow: file → dashboard → report → deck. For open-ended conversation, code generation in arbitrary languages, image creation, or general assistance, ChatGPT is the right tool. For analyzing your actual data, DuckViz costs less and exposes less.

Stop billing yourself for column headers.

Drop a file. Get the dashboard. Pay one credit. Your rows stay on your machine.

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