00 — Overview

What Is Sub-Second Finality

TON Core is upgrading the blockchain to produce blocks significantly faster, targeting sub-second user-perceived transaction finality. The goal: end-to-end user interactions complete in under 1 second.

But the upgrading of the blockchain doesn’t automatically upgrade User Expirience. The blockchain core team delivers the speed. Ecosystem projects must adapt their apps to actually deliver it to users.

Current Status

Mainnet validators were updated on February 12, 2026 with Catchain 2.0 and the new accelerated network layer. The new functionality has not yet been enabled and will be activated after testnet testing is complete. No fixed activation date has been announced.

The testnet has been running stably since the January 23, 2026 update with Sub-Second mode active. Testing is open — start now.

Network Block interval Blocks per second Pending lag Finalization lag
Mainnet today ~2.5 seconds ~0.4 BPS ~30-100ms ~10s
Testnet today ~450 ms ~2.2 BPS ~30-100ms ~4s
Mainnet target 200–400 ms ~2.5-5 BPS ~30-100ms ~2s

Testnet is already running close to the target speed. This is where you test.

Examples of Sub-Second UI

telegram-cloud-document-2-5282995131983630675.mov

The first products — MyTonWallet and tonscan.org — have already switched to Streaming API V2 on the main and test networks.

This has already nearly halved the operation time in these products, even though the blockchain itself is still operating in the same mode.

Video with example: https://t.me/anatolii_makosov/110

What Projects Need to Do

If you're building a wallet or app

A faster chain alone does nothing for your users if your app still polls HTTP endpoints. Users will continue seeing 10+ second delays.

Action: