Backtrader vs Zipline Reloaded (2026)
Backtrader (free open-source event-driven backtesting framework for python, no longer actively maintained) and Zipline Reloaded (maintained open-source fork of quantopian's event-driven python backtesting engine) solve backtesting differently. The table below compares them on verified specs and pricing; full details are in each review.
Side by side
| Backtrader | Zipline Reloaded | |
|---|---|---|
| Overall score | 6.8 / 10 | 6.7 / 10 |
| Engine type | event-driven | event-driven |
| Pricing model | open-source | open-source |
| Free tier | Yes | Yes |
| Entry price | $0 | $0 |
| Languages | Python | Python (3.9+, wheels through Python 3.13 as of v3.1.1) |
| Asset classes | stocks, ETFs, futures, forex (spot), crypto (via community data feeds), CFDs | US equities, ETFs, futures (continuous futures support), crypto/other via custom bundles and calendars (community workarounds) |
| Bundled data | None. Bring your own data. Loaders exist for CSV, pandas DataFrames, and Yahoo Finance (the online loader breaks periodically as Yahoo changes its API); live feeds come from Interactive Brokers, Oanda (legacy v1 API), and Visual Chart. No bundled historical dataset of any kind. | No usable current data ships with the library. The default Quandl/WIKI bundle (via NASDAQ Data Link) covers US equities only through March 2018, so you bring your own: either the csvdir bundle, which takes OHLCV CSVs with splits and dividends, or your own custom bundle ingest code. |
| Finest resolution | tick (tick data supported; resampling/replay down from ticks to any timeframe) | minute |
| Live trading | Yes | No |
| Options support | No | No |
| Open source | Yes | Yes |
Backtrader
Free open-source event-driven backtesting framework for Python, no longer actively maintained
Zipline Reloaded
Maintained open-source fork of Quantopian's event-driven Python backtesting engine
Frequently asked questions
Is Backtrader better than Zipline Reloaded?+
They target different users. Backtrader: python-comfortable retail quants who want a free, battle-tested event-driven backtester with abundant learning material, and who will accept a frozen codebase, byo data, and manual walk-forward in exchange for zero cost. Zipline Reloaded: python-fluent quants doing us-equity, factor-based (cross-sectional) research who want a free, realistic event-driven engine and are willing to wire up their own data pipeline. Our scores: Backtrader 6.8/10, Zipline Reloaded 6.7/10.
Which is cheaper, Backtrader or Zipline Reloaded?+
Backtrader entry pricing: $0 (open-source). Zipline Reloaded: $0 (open-source). See each review for full verified pricing tables.
Educational content only, not investment advice. Specs and prices come from each platform's official pages; see the individual reviews for sources and last-verified dates.