WhatTheDuck
WhatTheDuck is a browser-based SQL editor for CSV and Parquet files built on DuckDB. Users upload data files, query them with SQL, and download results—all processed locally without server transmission. Data persists only during the session.
Key facts
Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.
| Field | Value |
|---|---|
| Repository | incentius-foss/WhatTheDuck |
| Owner | incentius-foss |
| Primary language | Vue |
| License | MIT — OSI-approved |
| Stars | 629 |
| Forks | 28 |
| Open issues | 1 |
| Latest release | Unknown |
| Last updated | 2026-05-12 |
| Source | https://github.com/incentius-foss/WhatTheDuck |
What WhatTheDuck is
Vue.js frontend application leveraging DuckDB's in-browser SQL engine to enable client-side CSV/Parquet analysis. Uses Quasar framework for development; supports multi-file joins and exports filtered results to CSV. No persistent backend; data stored in browser memory.
Get the WhatTheDuck source
Clone the repository and explore it locally.
git clone https://github.com/incentius-foss/WhatTheDuck.gitcd WhatTheDuck# follow the project's README for install & configurationNeed it deployed, integrated, or customized instead? DEV.co ships production installs.
Best use cases
Implementation considerations
- Installation via Yarn/npm and Quasar build tooling; production deployment requires static hosting (e.g., Vercel, S3 + CloudFront). Docker Compose available for local dev.
- Session-only data means no persistence layer—verify use case tolerates data loss on refresh or browser close.
- DuckDB runs in browser; monitor performance and memory usage with intended file sizes and query complexity.
- No environment configuration for API keys, backends, or secrets evident; deployment is primarily configuration-less.
- Single Vue app; no backend code to maintain or scale, but also no server-side computation or external integration hooks.
When to avoid it — and what to weigh
- Persistent Data Storage Required — Session-only memory storage means all data is lost on page refresh. Not suitable for applications where historical records or audit trails are mandatory.
- Large Dataset Processing — Browser memory constraints limit practical dataset size. Unknown how performance scales; browser-based execution may be insufficient for multi-GB analyses.
- Production Critical Workflows — No release versioning, unstable deployment story, and single maintainer structure indicate maturity risks. Unsuitable for mission-critical or compliance-regulated environments.
- Collaborative Multi-User Access — No authentication, authorization, or multi-user session management evident. Each user operates in isolation; no sharing or concurrent access support.
License & commercial use
Licensed under MIT (MIT License), a permissive OSI-approved license. Permits use, modification, and distribution with minimal restrictions; attribution appreciated but not legally required.
MIT License permits commercial use. However, verify your use case does not rely on undocumented features, SLA guarantees, or vendor support. No commercial support or warranty is stated. For production deployments, consider whether lack of formal maintenance and versioning aligns with your risk tolerance.
DEV.co evaluation signals
Editorial assessment — not user reviews. Directional, with an explicit confidence level.
| Signal | Assessment |
|---|---|
| Maintenance | Moderate |
| Documentation | Adequate |
| License clarity | Clear |
| Deployment complexity | Low |
| DEV.co fit | Good |
| Assessment confidence | High |
Data processing occurs locally in the browser (WASM-based DuckDB). No data transmission to external servers claimed in README. However: unknown code-signing, dependency audit status; WASM security boundary relies on browser sandbox; no input validation/sanitization details; no rate limiting or DOS protections; suitable for trusted or personal use, but verify WASM supply chain and browser security model for sensitive data. Consider integrity of hosted assets (CSP, subresource integrity).
Alternatives to consider
Observable / Observable Plot
Browser-based data exploration with SQL-like queries and visualization; more mature, funded, and designed for collaborative notebooks. Steeper learning curve and vendor lock-in.
Metabase (self-hosted)
Full-featured open-source BI platform with persistence, multi-user support, and scheduling. Requires backend deployment and database setup; overkill for ad-hoc exploration.
SQL.js or SQLite Web
Similar in-browser SQL engines; SQLite Web offers a simpler UI for SQLite. Less mature ecosystem than DuckDB; fewer data format options.
Build on WhatTheDuck with DEV.co software developers
Best suited for ad-hoc analysis and exploratory queries. If you need persistence, multi-user access, or production guarantees, discuss alternatives with our team.
Talk to DEV.coRelated open-source tools
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WhatTheDuck FAQ
Is my data stored on a server?
Can I use WhatTheDuck for production analytics?
What data formats are supported?
Can multiple users access the same session?
Work with a software development agency
Adopting WhatTheDuck is usually one piece of a larger software development effort. As a software development agency, DEV.co provides software development services and web development expertise — pairing senior software developers and web developers with your team to design, build, and operate open-source databases software in production.
Evaluate WhatTheDuck for Your Data Workflow
Best suited for ad-hoc analysis and exploratory queries. If you need persistence, multi-user access, or production guarantees, discuss alternatives with our team.