Instant Finality
Ultra now delivers Instant Finality: transactions become irreversibly final in about 1 second, down from the multiple minutes required by the previous consensus. It was activated on Mainnet as part of the Antelope Spring 1.x upgrade.
TL;DR
Before: a transaction took up to ~3 minutes to become irreversible. Now: ~1 second — a greater than 100x improvement in time-to-finality, with stronger, cryptographic security guarantees.
What "finality" means
Finality is the moment a transaction becomes permanent and irreversible — it can never be undone or rolled back by a chain reorganization. Until a transaction is final, anyone relying on it (an exchange, a marketplace, a game) must wait to be safe. Faster finality makes everything faster and safer.
Why it matters
For everyone
- Near-instant settlement. Payments, token transfers, NFT/Uniq trades, and in-game actions are locked in within ~1 second.
- A web2-like experience. No more watching a spinner for minutes — confirmations feel instant.
- Stronger guarantees. Once a transaction is final, it is mathematically irreversible — not just "probably" safe.
For developers
- Instant-confirmation UX. React the moment a transaction is final, instead of polling through long "pending" states.
- Faster deposits & withdrawals. Exchanges and bridges can credit Ultra transactions in ~1 second instead of minutes, cutting settlement risk.
- Simpler logic. Deterministic finality removes the guesswork of "how many confirmations are safe enough."
- No migration required. Your existing contracts and dApps simply finalize faster — no code changes needed.
How it works
Instant Finality is powered by Savanna, a Byzantine Fault Tolerant (BFT) consensus protocol (inspired by the HotStuff algorithm). It separates two responsibilities that used to belong to a single role:
- Block Proposers produce blocks, as before.
- Block Finalizers vote on blocks by signing them.
Finalizer votes use BLS signatures, which aggregate into a single compact Quorum Certificate (verified in ~1.1 ms). Once a supermajority of finalizers has signed a block, that block is final — cryptographically and permanently.
Ultra still uses Proof of Authority
Instant Finality changes how fast blocks become final — it does not change who produces them. Ultra continues to use Proof of Authority with its carefully selected Block Producers; the Savanna protocol provides this finality layer on top.
Compared to the previous protocol
| Before (legacy) | Now | |
|---|---|---|
| Time to finality | up to ~3 minutes | ~1 second |
| Finality type | delayed confirmation | cryptographic & deterministic |
| Producer roles | single role | Proposers + Finalizers |
| Scaling producers | slowed finality | add producers without slowing finality |
Ultra vs. other blockchains
Finality is where Ultra stands apart. Compared with other major chains:
| Blockchain | Time to finality | Finality type |
|---|---|---|
| Ethereum | ~13–15 minutes | deterministic |
| Solana | ~13 seconds | deterministic (BFT) |
| Ultra | ~1 second | deterministic (BFT) |
Figures are typical real-world values and vary with network conditions.
Is it secure?
Yes — more secure than before. Instant Finality provides deterministic finality backed by BFT cryptography: a block is final only after a supermajority of finalizers has cryptographically signed it, and a final block can never be reverted. This is a stronger guarantee than the probabilistic finality used by chains like Bitcoin, where "final" only ever means "extremely unlikely to be reversed."
Learn more
- Consensus — how Ultra's Proof of Authority works
- Block Production — how blocks are produced on Ultra