Cardano’s Leios Upgrade Targets 5x Transaction Capacity, With a Path to 15x

TL;DR

• Cardano’s Leios upgrade targets an initial 3x to 5x increase in transaction data capacity, with a potential expansion toward 15x through separate governance approvals.
• Input Output’s rollout plan requires stake pool operators to register BLS voting keys and demonstrate reliable network performance before capacity increases.
• Previous testing reached nearly 6x Cardano’s current Praos capacity, while mainnet traffic exercises will determine whether higher throughput targets are achievable.
  

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Cardano’s Leios upgrade is moving toward a staged deployment designed to increase transaction throughput without sacrificing the network’s decentralized architecture. Input Output’s October 20 update outlines an initial capacity target of five times current levels, with a longer-term path toward 15x, subject to testing and governance approval.

Currently 21 of the 103 apps listed on https://t.co/XXRKmcOmRb have transaction tracking switched on. Once it is enabled, an app appears on the leaderboard. Tracking is open to all projects building on Cardano.https://t.co/YnvMr2ba6H pic.twitter.com/aeeahOen1F

— Cardano (@Cardano) October 20, 2026

How Cardano’s Leios Upgrade Plans To Scale Throughput

The rollout begins with the Dijkstra hard fork, which introduces the protocol changes needed for Leios. Activation requires additional preparation, including stake pool operator registration and protocol parameter updates. Input Output estimates that voting keys must cover approximately 90% to 95% of delegated stake to provide sufficient participation.

Leios introduces endorser blocks alongside Cardano’s existing Praos ranking blocks. Endorser blocks help handle transactions awaiting processing, allowing the network to expand its capacity beyond the limits imposed by its current block-production system. This architecture is designed to increase throughput without replacing Cardano’s existing consensus foundation.

The design also relies on Boneh-Lynn-Shacham (BLS) signatures, which combine multiple pool votes into compact certificates. Input Output says endorser blocks require votes representing at least 75% of active stake for certification. Pools that have not registered voting keys can continue producing Praos blocks but cannot participate in endorser-block voting.

This approach gives Cardano a route to greater throughput while retaining participation from existing stake pools. However, the upgrade’s availability after Dijkstra does not automatically activate its full capacity, making registration and subsequent network testing essential to the rollout.

Testing Results And Governance Will Determine Expansion

Earlier engineering tests provide an indication of Leios’ potential. In an August 20 report, the development team recorded a peak of 26.8 TxkB/s on MusashiNet, compared with a Praos mainnet ceiling of approximately 4.51 TxkB/s. That represents nearly six times the baseline, although the result came from a test environment rather than live mainnet activity.

Input Output plans controlled bursts of mainnet traffic to assess block delivery, voting speed, certificate reliability and node performance. These measurements will inform successive capacity increases, with separate governance approvals required for later parameter changes.