For traders developing algorithmic strategies (specifically backtesting) who need high-quality Tick Data without paying expensive vendor fees, Dukascopy is arguably the best source available to retail traders.
If you are building a machine learning model to predict the next 1-minute move, Dukascopy is arguably the best free source of training data available to the public. dukascopy historical data
To download the raw data efficiently, you generally have to use their proprietary platform, (Java-based) or the older JForex 2. and selected individual stocks/ETFs.
Includes FX majors/minors, metals (Gold/Silver), energy (Oil), global indices, and selected individual stocks/ETFs. dukascopy historical data