TON launches an ultra-fast, sub-second upgrade; the mainnet will be fully activated by April 7

TON core team has announced that the Catchain 2.0 consensus mechanism upgrade (Sub-Second upgrade) has entered the mainnet deployment phase. The goal is to compress the block finalization time from the current ~10 seconds to about 1 second, and reduce the block interval from about 2.5 seconds to 200-400 milliseconds. On April 2, validators voted to activate the new consensus mechanism on the basechain. On April 7, the basechain and mainchain fully enabled the fast consensus mechanism.

Technical Benchmarks: Catchain 2.0 brings TON confirmation speed close to Web2

Catchain 2.0 is TON’s core consensus-layer upgrade, designed to achieve sub-second finality and bring the on-chain experience in terms of responsiveness closer to traditional Web2 services. The comparison across three key performance dimensions is as follows:

The current mainnet block interval is about 2.5 seconds, or about 0.4 blocks per second, with finalization lag of about 10 seconds; the testnet currently has a block interval of about 450 milliseconds, with finalization around 1-2 seconds; after the upgrade, the mainnet targets a block interval of 200-400 milliseconds, about 2.5-5 blocks per second, and finalization lag of about 1 second.

At the same time, TON Center has released Streaming API v2, providing push-based transaction status updates, with latency from on-chain events to the client of 30-100 milliseconds. MyTonWallet and tonscan.org have adopted this new API. Even before sub-second confirmations are enabled on the mainnet, the transaction response times of these products have already been cut by nearly half.

Three-Phase Deployment Schedule: Node Task Checklist

The mainnet deployment of the Sub-Second upgrade is progressing according to strict time milestones:

March 31: All validator nodes complete version updates, upgrading to the latest version that supports Catchain 2.0

April 2: Validators vote to activate the new consensus mechanism on the basechain, increasing block production frequency, and fast consensus goes live

April 7: The basechain and mainchain synchronously and fully enable the fast consensus mechanism. The Sub-Second upgrade is completed and activated across the entire TON mainnet

The Core Paradox of the Upgrade: Faster Chain Speed but Apps Don’t Catch Up

In its technical announcement, TON specifically emphasized the key blind spot of this upgrade that is most likely to be overlooked: even if the underlying blockchain generates blocks at 10x speed, if projects continue using HTTP polling instead of the Streaming API, the transaction status update latency in the user interface may still exceed 10 seconds.

Take HTTP polling as an example: after a user clicks “send,” the transaction is included in a shard block in about 0.4 seconds and submitted to the mainchain in about 0.8 seconds. However, the UI update must wait for the next polling request, which may delay it by more than 10 seconds. But after switching to Streaming API v2, it shows a pending status in 0.1 seconds, a confirmed status in 0.4 seconds, and a finalized status in 0.8 seconds—completing the entire process within 1 second.

The TON core team clearly warns: “If an application cannot adapt, even if the underlying system is functioning normally, the upgrade will appear ineffective. Projects that are ready before the mainchain goes live will be able to demonstrate the expected behavior and user experience.”

Frequently Asked Questions

What is the fundamental difference between Catchain 2.0 and the earlier TON consensus mechanisms?

Catchain 2.0 is a major upgrade to TON’s consensus layer. The core change is significantly shortening the block production interval (from about 2.5 seconds down to 200-400 milliseconds) and the finalization time (from about 10 seconds down to about 1 second). Block throughput per second increases by about 2.5-5x, making TON’s on-chain interaction responsiveness, by design, close to the standards of traditional Web2 services.

What specific adaptations do application developers in the TON ecosystem need to make?

The main adaptations are concentrated in three areas: first, switch to TON Center Streaming API v2 to receive push-based transaction status updates and replace HTTP polling; second, handle all four transaction status types (pending, confirmed, finalized, trace_invalidated) and update the UI accordingly; third, if running self-hosted nodes, update to the latest version that supports Catchain 2.0 before April 7. Exchanges and payment services that use external APIs do not need to take any additional actions.

What does TON’s Sub-Second upgrade mean for ordinary users?

For ordinary users, the most direct change is that when using upgraded wallets, dApps, and payment services that have been adapted, transfer confirmation speed will be drastically reduced from about 10 seconds to within 1 second. However, this improvement completely depends on whether the project team has completed the Streaming API adaptation—unadapted applications, even if running on the upgraded mainnet, will not provide any noticeable improvement to the user experience.