UPDATE
Bitfinex Paper Trading - Demo trading on the Bitfinex exchange by creating a paper trading sub-account. To access the demo, you need to register an account on the exchange, and then create a sub account for demo trading.
In the sub account, create an API key and load the Honey Framework application on your computer. Further trading TESTBTC, TESTUSDT, TESTUSD, TESTAAA and TESTBBB will be available. The balance for demo trading is a maximum of $ 1 000 000.
Detailed instructions here:
https://support.bitfinex.com/hc/en-us/articles/900001525006-Paper-Trading-test-learn-and-simulate-trading-strategies-
BitGet - Demo trading on the BitGet exchange. To access demo trading, you need to register an account.
After registration in the futures tab, the Demo account tab will appear. By clicking on the link, futures trading in the SBTC\USD pair will be available, the balance of 0.5 SBTC is available for this pair, for the BTC\USDTSL, ETH\USDTSL, EOS\USDTSL pairs, the balance of 5000 SUSDT is also available, in each pair. All pairs are represented by trading in perpetual contracts.
Crypto Parrot - Demo trading platform. Account registration is required to access demo trading.
After registration, a balance of $100 000 will be credited. More than 20 cryptocurrencies are available for demo trading. Spot trading.
Bitcoin Flip - Bitcoin trading simulator. Registration is not required. You can trade in guest mode, but with some restrictions.
In guest mode, only BTC, LTC, XRP, ETH are available. If you register, you will have access to 20 more cryptocurrencies. For demo trading, $10 000 is available. You can trade both in spot and in margin mode. The maximum leverage is x5.
Altcoin Fantasy - Demo trading platform. Registration is required to access demo trading.
After registration, you will have access to $10 000. There are 14 crypto assets to choose from for demo trading. Spot trading.