# Advantages

Compared to other solutions to generate proofs of timestamps (both off-chain and on-chain), you can find in tProof the following main advantages:

* **Decentralized**: anyone can interact with our smart contracts
* **Single upfront payment**: you pay once to generate the certification, and it will last forever
* **Clear Ownership**: certifications are owned by you, stored inside your wallet
* **NFT-based**: implementing ERC-721 standards, each proof is managed through an NFT, containing metadata to better identify the proof, while making easier it's transfer or trade
* **Multi-chain**: works on different chains, while keeping a unique ID across them
* **Flexible**: files can be kept private, with just the hash being published, or made public via a Chainlink Oracle system