Celestia activates Fibre, enabling direct validator uploads for rollups

Celestia has switched on Fibre, a new high-throughput lane for rollup data, on its mainnet. Activation came on approximately October 20, 2026, after validator signaling crossed the required 83.33% voting power threshold.

Fibre works as a parallel data availability layer. It is run by the same validator set that already secures Celestia, so no new operators are involved.

Data availability is the plumbing that lets rollups prove their transaction data was actually published. Without it, nobody can check that a rollup is telling the truth about its own history.

Celestia normally handles this through its L1 “data square,” a structured layout that data gets packed into for each block. Fibre steps outside that process. Blobs, the chunks of data rollups submit, go straight to validators.

The checks still happen. Commitments and validator signatures continue to land on-chain, so there is still a public record that the data was received and attested to.

The launch numbers

The initial release has firm limits. A single Fibre blob can be up to 128 MiB, and each block can hold up to 200 Fibre submissions.

There is also a floor. The minimum blob size is set at 256 KiB, which signals that Fibre is built for heavy loads, not tiny transactions.

Rollups now get a choice of two paths. The standard Celestia L1 route handles blobs up to 8 MiB and relies on sampling-based verification. Fibre handles much larger payloads, making the maximum Fibre blob 16 times bigger than the standard L1 ceiling.

In an October 2026 benchmark, Fibre sustained 3.07 Tb/s of throughput across 120 validators. An earlier test in January 2026 reached 1 Tb/s across roughly 500 nodes.

The mainnet version runs with smaller uploads and a slower block cadence than the terabit benchmark setup.

Where TIA fits in

Celestia’s native token, TIA, handles three jobs tied to Fibre: staking, escrow deposits, and fee payments.

Fibre fees are built from two parts. One component scales with the size of the data submitted, and the other is a base fee.

The escrow deposit requirement links Fibre usage directly to demand for the token, as users of the high-throughput lane need to lock up TIA.

The background: governance by validator vote

Fibre did not arrive by decree. It needed validators holding 83.33% of voting power to signal support before it could activate.

Those same validators now take on extra work, running a parallel data pipeline next to normal block production. The roughly ten months between the January 2026 test and the October activation reflect a staged rollout through testnet implementations including Mocha, culminating in the mainnet launch of Celestia’s Fibre v10 app.

What this means for rollups and the DA market

Rollups that need cheap, sampling-verified data storage can stay on the standard L1 path. Rollups with very large data needs can move to Fibre. The research behind this report identifies high-throughput sectors such as AI and microtransactions as potential fits, workloads that produce large amounts of data consistent with the 256 KiB minimum.

Fibre skips the standard data square, so its security rests more heavily on validators confirming they hold the data, whereas the standard L1 path offers sampling-based verification.

The gap between benchmark and launch limits is the other thing to track. The test hit 3.07 Tb/s, while mainnet is running with smaller uploads and a slower cadence. How quickly those limits get raised will show how confident the network is in Fibre under real conditions.