OpenTax review
A transparent, self-hostable tax preparer for technical users who value control.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
OpenTax is an open-source US tax preparation application for individuals who want transparent computation and control over their tax workflow. It imports W-2s, 1099s, and other tax documents, then guides users through a tax interview covering federal and supported state returns. The application generates IRS-ready PDFs for printing and mailing and includes paper filing guidance. Its computation runs locally in the browser, making the product particularly relevant to technical users who prefer open software, self-hosting, or programmatic access.
Pricing is straightforward: the Free plan costs $0 and is free forever. It includes open-source tax preparation, all features, and no account requirement, so there is no paid tier to evaluate or upgrade into. The published plan also covers document import, guided preparation, deterministic tax computation, supported-state preparation, PDF generation, and the OpenClaw plugin. This makes OpenTax a strong fit for individuals seeking a fully available free workflow rather than a limited trial or a product that reserves core preparation features for paid plans.
The product’s standout strength is traceability. Calculations are linked to source documents and IRS rules, while deterministic computation provides a defined basis for reviewing results. Its platform fit is also broader than a browser-only tool: OpenTax supports web, API, and self-hosted use, with REST, SSE, and 16 agent tools available through the OpenClaw plugin for AI-assisted preparation. The tradeoff is filing scope and guidance depth. Electronic filing is not currently supported, and the product does not include expert review or verified deduction discovery. Choose OpenTax if transparency, local computation, and integration flexibility matter most; choose an alternative if electronic filing or professional deduction review is central to your workflow.
OpenTax pros and cons
- Where it wins
- Free forever with every feature included and no account required
- Traceable calculations link values to source documents and IRS rules
- Web, API, and self-hosted access with OpenClaw agent tools
- Where it doesn't
- Electronic filing is not currently supported
- State preparation is limited to supported states
- No expert review or verified deduction discovery
OpenTax fact sheet, pricing and score →
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update