Frankfurter review
An open, free API for developers who need historical and daily currency rates.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Frankfurter is an open-source exchange-rates API for developers building currency features into software, spreadsheets, data workflows, or internal tools. It provides daily foreign-exchange data from central banks and other official sources, with support for 223 currencies. The public REST API is free, requires no API key, and can also be deployed privately with Docker. Its audience is technical teams and individuals who need programmable rates rather than a consumer-focused mobile conversion experience.
The free service combines current rates with historical lookups and time-series queries reaching back to 1948. Provider-specific rate queries, provider attribution, currency and provider directory endpoints, and CSV or NDJSON responses give developers control over how rate data is retrieved and represented. Integrations for Excel, Google Sheets, JavaScript, MCP, pandas, and Python extend the same data into common development and analysis environments. For organizations that need more control over deployment, the self-hosted option provides a private Docker instance while preserving the API model.
Frankfurter’s main constraint is its daily refresh schedule, which may not suit applications requiring intraday or real-time market movements. Its API-first design also means teams seeking a ready-made consumer converter will need to build their own interface or choose a dedicated app instead. Developers who value open-source access, long historical coverage, official-source data, and flexible output formats should find a strong fit here; teams prioritizing frequent updates or a polished end-user mobile experience should look elsewhere.
Frankfurter pros and cons
- Where it wins
- 223 currencies with daily data from central banks and official sources
- Historical rates and time-series queries dating back to 1948
- REST access without an API key plus Docker self-hosting
- Where it doesn't
- Daily refresh may not fit applications needing intraday rates
- API-oriented design is not a consumer mobile converter
- Private deployment requires Docker-based self-hosting
Frankfurter fact sheet, pricing and score →
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