Polygon, Polkadot Ship April Upgrades; Ethereum Plans Glamsterdam

April Blockchain Upgrades: Live Forks and Planning Phases

In April 2026, blockchain protocols took divergent paths—some delivering live mainnet changes, others refining future architectures. Polygon’s Giugliano hard fork activated on April 8, Polkadot executed Runtime v2.1 through governance in late April, and BNB Chain prepared the Osaka/Mendel fork for April 28 at 02:30 UTC, according to the protocol announcements reviewed.

Polygon Giugliano: Mainnet Stability Focus

Polygon’s Giugliano hard fork went live on April 8, 2026, introducing faster confirmations, on-chain fee-parameter introspection, higher P2P throughput, and re-enabled snap sync. The upgrade was designed to improve chain legibility for wallets and payment applications and enhance resilience under high demand. According to the source material, Polygon reported the activation as clean with no outages or exploits detected.

Polkadot Runtime v2.1: Governance-Driven Execution

Polkadot’s Runtime v2.1 was approved and executed through on-chain governance in late April, bypassing the need for a hard-fork ceremony. The update included Bulletin chain phase 0 for content-addressed ephemeral storage, elastic scaling with 2-second block times on People, and a 10x reduction to the smart-contract storage deposit parameter on Asset Hub. This approach reflects Polkadot’s governance-based upgrade model, enabling feature rollouts without operator-coordinated forks.

BNB Chain’s Mendel Fork: Predictability Over Speed

BNB Chain’s Osaka/Mendel hard fork was scheduled for April 28, 2026, at 02:30 UTC. According to the source, the fork materials and v1.7.2 tag were released early in April, signaling a philosophical shift toward execution stability and a protocol-level per-transaction gas cap. The gas cap, conceptually borrowed from Ethereum’s EIP-7825, establishes a hard ceiling on transaction complexity to reduce pathological transactions and improve capacity planning.

Ethereum and Tezos: Architecture Planning in April

Ethereum’s Checkpoint #9, updated on April 13, 2026, indicated that Glamsterdam in Q2 was unlikely. The roadmap frames Glamsterdam as the next major upgrade focused on parallelization, expanded capacity through separation of duties, and state-growth sustainability. Following Fusaka’s December 2025 activation, Glamsterdam represents the next significant architectural step rather than a quick follow-up.

Tezos surfaced the Ushuaia proposal during April discussions, introducing enshrined liquid staking—a protocol-level sTEZ token behind a feature flag. The proposal also includes DAL bandwidth increases, dynamic attestation timing, and early quantum-resistant account support. While not yet activated, the amendment signals a direction toward improved capital efficiency across the ecosystem.

Chains with No Reported April Protocol Changes

For Cardano, Solana, and Cosmos Hub, no implemented protocol changes meeting primary-source criteria were identified for April 1–27, 2026. Cardano’s signals pointed toward the Van Rossem hard fork later in the cycle; April activity focused on governance and a minor node regression fix. Solana’s April activity remained in forum discussions and research proposals. Cosmos Hub had governance traffic and client-update mechanics but no new software-upgrade entry comparable to prior Gaia upgrades. Bitcoin, Avalanche, NEAR, Algorand, and TRON also did not surface implemented protocol changes during this window, according to the source review.

The Broader Pattern

April 2026 reflected a maturing blockchain ecosystem prioritizing governance-driven upgrades (Polkadot), fee legibility and mempool resilience (Polygon), and execution stability over headline speed metrics (BNB Chain). Ethereum and Tezos focused on defining next-generation architectures without live mainnet forks, demonstrating that significant protocol work occurs outside of fork events.