I write a smart contract and want to use oraclize for getting random number. Are there any differences between those methods:

Using WolframAlpha:

oraclize_query("WolframAlpha", "random number between 1 and 2^64");

Using Random.org:


Using oraclize random method:

bytes32 queryId = oraclize_newRandomDSQuery(delay, N, callbackGas); 

In term of price, I see that:

  • WolframAlpha: 0.03$/query. unlimited queries.
  • Random.org: 0.01$/query. only 1000 requests/day (limited by random.org)
  • oraclize_newRandomDSQuery: 0.05$/query.

Please tell me differences in functionality. Thanks

1 Answer 1


The random data source query is designed so that assuming the ledger hardware enclave isn't compromised, your contract can verify that Oraclize really gave you a random number.

Using Wolfram Alpha or random.org require you to trust those organisations, plus Oraclize and their CDNs, any of whom could cheat undetectably.

  • thanks. so in production we should use random data source query, right ?
    – hqt
    Jun 9, 2018 at 11:55
  • Yes, if you can afford it for your use-case. Or better, if possible design your thing so you don't have to use a third-party service... Jun 10, 2018 at 3:13
  • 1
    Thanks so much :D I have a problem when using "oraclize_newRandomDSQuery" function. Can you help me to figure out. I ask here: ethereum.stackexchange.com/questions/50857/… thanks
    – hqt
    Jun 10, 2018 at 12:00

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