What is EIP-4844?
EIP-4844, also known as Proto-Danksharding, is an Ethereum upgrade that introduced a new data storage format called blobs (Binary Large Objects). Blobs allow Layer 2 rollups to publish their transaction data to Ethereum at a fraction of the previous cost.
Activated on Ethereum mainnet in March 2024 as part of the Dencun upgrade, EIP-4844 reduced L2 transaction fees by 10–100x overnight.
The Problem It Solves
Before EIP-4844, rollups had to publish all transaction data as regular Ethereum calldata — which is expensive because it’s processed by every node and stored permanently:
Before EIP-4844:
Arbitrum publishes 100,000 txs as calldata
→ Every Ethereum node processes + stores it forever
→ Cost: $0.50–$2.00 per L2 transaction
After EIP-4844:
Arbitrum publishes 100,000 txs as blobs
→ Blobs are verified but not processed by all nodes
→ Stored only for ~18 days then pruned
→ Cost: $0.01–$0.05 per L2 transactionHow Blobs Work
Blob vs Calldata
| Feature | Calldata (old) | Blobs (new) |
|---|---|---|
| Processed by EVM | Yes | No |
| Permanent storage | Yes | ~18 days then pruned |
| Max size per block | Unlimited (but expensive) | ~128 KB per block (~6 blobs) |
| Cost | High (permanently stored) | Low (ephemeral) |
| Verification | Full processing | Data availability sampling |
Why Temporary Storage Is Fine
Rollups don’t need their data stored permanently on L1. They need it to be available long enough for anyone to verify or challenge it. Since Optimistic rollups have a 7-day challenge window, 18 days of blob availability is more than sufficient.
After 18 days, the data is pruned from most nodes. Full historical data remains accessible via archive nodes and decentralized storage.
The Blob Fee Market
EIP-4844 introduced a separate fee market for blobs with its own base fee (similar to EIP-1559 for regular transactions). This means:
- Blob fees don’t compete with regular transaction fees
- When blob demand is high, blob base fee increases independently
- Regular users (transfers, DeFi) aren’t affected by L2 data publication
Fee Impact
The fee reduction was immediate and dramatic:
| Network | Before EIP-4844 | After EIP-4844 | Reduction |
|---|---|---|---|
| Arbitrum | $0.50–$2.00 | $0.01–$0.10 | ~95% |
| Optimism | $0.40–$1.50 | $0.01–$0.08 | ~95% |
| Base | $0.30–$1.00 | $0.01–$0.05 | ~95% |
| zkSync Era | $0.50–$2.00 | $0.05–$0.20 | ~90% |
This made L2 transactions cheaper than many alternative L1s (Solana, BNB Chain) for the first time.
EIP-4844 vs Full Danksharding
EIP-4844 is the “proto” (prototype) version of full danksharding. It implements the transaction format and fee market but with limited capacity:
| Feature | EIP-4844 (Now) | Full Danksharding (Future) |
|---|---|---|
| Blobs per block | ~6 (~128 KB) | ~64+ (~2 MB+) |
| Data sampling | No (full download) | Yes (DAS — light nodes verify) |
| L2 throughput | ~100–500 tx/s | ~100,000+ tx/s |
| Status | Live since March 2024 | Research phase |
Full danksharding adds data availability sampling (DAS), which lets light nodes verify blob availability without downloading full blobs — enabling massive scaleup.
Impact on the L2 Ecosystem
EIP-4844 was a game-changer for L2 adoption:
- Base surpassed Ethereum mainnet in daily transactions
- Arbitrum and Optimism fees dropped below $0.10
- Coinbase’s Base became a major L2 hub for consumer apps
- L2 TVL grew significantly as DeFi migrated from L1
Frequently Asked Questions
Q: Did EIP-4844 make Ethereum mainnet cheaper? A: No. It only reduced L2 (rollup) fees. Ethereum L1 transaction costs are unaffected.
Q: What happens to blob data after 18 days? A: It’s pruned from most nodes to save disk space. Archive nodes and protocols like Celestia retain it. Rollups keep their own data.
Q: Can blobs be used for regular transactions? A: No. Blobs are designed for L2 data publication. Smart contracts can’t read blob contents directly — they can only verify the blobs exist.
Q: Why is it called “Proto-Danksharding”? A: “Proto” = prototype. “Danksharding” is named after Dankrad Feist, an Ethereum researcher. EIP-4844 is the stepping stone to full danksharding.