Across vs Stargate vs Relay vs LI.FI: What's the Difference?

"Across vs Stargate vs Relay vs LI.FI" is one of the most common cross-chain comparisons, and it is usually framed wrong - as if all four were competing bridges you pick between. In reality they occupy different layers. Getting the layers right is the whole point, because it tells you what you are actually choosing when you use each one. This article explains each, how they work, and how they relate.

The layers, first

• Bridge protocol: moves value with one mechanism and one trust model (Across, Stargate).
• Routing/execution provider: finds and executes a route quickly, often fronting liquidity for fast fills (Relay).
• Aggregator: compares many protocols per transfer and routes through the best one, moving no value itself (LI.FI).

So a fair comparison is not "which of the four is the best bridge," but "what does each do, and where does it sit." An aggregator like LI.FI can route a transfer through Across or Stargate; a router like Relay can be an independent path or a fallback. They compose.

Across

Across is an intents-based, optimistic bridge protocol. You express an intent to receive an asset on the destination chain, and a relayer immediately fronts you the funds from its own capital, then reclaims the amount from the source chain afterwards - secured by an optimistic verification model with a challenge window and a single hub-and-spoke liquidity pool. The practical result is fast fills for supported assets and competitive fees, because a relayer does not wait for full source-chain finality before paying you. Its trust model rests on the optimistic verification and the correctness of the relayer/settlement system.

Stargate

Stargate is a liquidity-pool bridge built on LayerZero messaging. It keeps unified pools of an asset across chains; your deposit is added to the source pool and the equivalent is paid from the destination pool, so you receive the real native asset rather than a wrapper. Because it is pool-based, transfer size is bounded by destination-pool depth and pricing can shift if a pool is imbalanced, and it pays a fee to liquidity providers. Its messaging trust model is LayerZero's; its value model is the shared pools.

Relay

Relay is a routing and execution provider optimised for fast, low-cost fills, and it supports a broad set of chains directly. In an aggregating interface it often serves as an independent path or an automatic fallback: when a primary aggregator returns no route for a specific pair, calling Relay directly can surface one. It is best thought of as another route source rather than a pool-based protocol - the value question (what backs your funds mid-transfer) still comes down to the specific fill mechanism used.

LI.FI

LI.FI is not a bridge protocol at all - it is an aggregator (and cross-chain DEX router). For a given transfer it queries many underlying bridges (including Across and Stargate) and DEXs, compares the routes, and returns the best one for an interface to execute. It can also combine steps - bridge on one leg, swap on another - into a single route. When you use LI.FI, the actual value movement is done by whichever underlying protocol it selected; LI.FI's role is selection and coordination.

Side by side

How they relate (and why it's not either/or)

Because LI.FI aggregates protocols, using LI.FI can mean using Across or Stargate under the hood - you are not choosing LI.FI instead of them, you are choosing to let a comparison layer pick between them. Relay can sit alongside as an additional route source. The strongest setups combine an aggregator (broad protocol coverage) with a direct fallback router (coverage the aggregator momentarily lacks), which is more robust than committing to any single one.

Which should you use?

• If you want the best route for a specific transfer without researching protocols: an aggregator (LI.FI) - it compares for you.
• If you specifically want intents-based speed for a supported major asset: Across is a strong underlying choice, and an aggregator will often select it anyway.
• If you want native-asset delivery via deep shared pools: Stargate is the pool model, again selectable via an aggregator.
• If a pair is momentarily unavailable through your aggregator: a direct router like Relay is a useful fallback.

How Titan Bridge uses them

Titan Bridge is a non-custodial bridge aggregator developed by Titan that automatically routes transfers across multiple bridge providers to optimise speed, cost, and reliability. Concretely, Titan routes through LI.FI - gaining its whole protocol set, including Across and Stargate - and calls Relay directly as an automatic fallback. So you get aggregator breadth plus a direct fallback path, and Titan never takes custody: your wallet signs the transaction that executes through whichever underlying route wins. In this article's terms, Titan is the interface and routing layer on top of all four.