Summary: Goerli is effectively end-of-life and Sepolia is now the default path for application testing, with Hoodi replacing Holesky for validator/staking workflows. This guide shows Enterprise teams exactly how to migrate builds, CI, faucets, and ZK/AA flows to Sepolia with minimal disruption, tying each step to measurable ROI, SOC2-driven procurement, and production readiness.

Target audience: Enterprise (keywords: SOC2, Procurement, RFP, SLA, ROI, DevSecOps)

Introduction to “Testnets” (Goerli, Sepolia)

You’re midway through user-acceptance testing when your Goerli pipeline fails: faucets rate-limit, RPCs decommission, and L2 “-goerli” endpoints 404. Your release plan assumes a stable pre-prod chain, but Goerli is sunsetting and L2s have already moved their testnets to Sepolia.

Concrete changes Enterprise teams must factor today:
- Ethereum app testing has consolidated on Sepolia (chainId 11155111). (ethereum.org)
- Goerli support was broadly deprecated across L1/L2s in Q1–Q2 2024; many providers switched off Goerli RPCs on or shortly after Apr 1, 2024. (alchemy.com)
- Holesky, launched for validator-scale testing, was sunset in 2025; Hoodi is the current validator/staking-focused testnet. Application developers should use Sepolia. (blog.ethereum.org)

If your pre-prod hinges on Goerli, the risk isn’t theoretical—it’s missed milestones, audit windows slipping, and procurement rework when vendors can’t meet SLAs on an obsolete network.

Agitate: What’s at stake if you don’t switch

Missed deadlines and QA drift
- L2s (Optimism, Arbitrum, Base) retired “-goerli” and require OP/Arbitrum/Base Sepolia. Your integration tests and bridges must be re-pointed or they fail. (alchemy.com)
Faucet friction and team throughput loss
- Goerli ETH scarcity turned into a liquid market in 2023; faucets became unreliable and rate-limited, slowing test cycles and onboarding. (blockworks.co)
Compliance and vendor risk
- Procurement will ask for SOC2, uptime SLAs, region pinning, and data-handling attestations. Several infra vendors updated their posture for Sepolia-era testnets (e.g., Chainstack SOC 2 Type II). (chainstack.com)
Cost modeling mismatch post-Dencun
- After EIP-4844 (Dencun), L2 costs dropped by ~90–98% thanks to blob transactions. Your gas budgets, fee alerts, and unit-economics models must be recalibrated on Sepolia and L2 sepolia testnets. (blog.ethereum.org)

The outcome: prolonged test cycles, inaccurate performance and cost forecasts, and delayed production cutovers.

7Block Labs’ pragmatic migration playbook (Solidity, ZK, AA) to Sepolia

We treat testnets as pre-production environments—measured, reproducible, and audit-ready—not “toy chains.” Here’s our blueprint to move cleanly off Goerli and standardize on Sepolia with downstream L2s, aligned to Enterprise security and procurement.

1) Network strategy: where each workload belongs

App and tooling testing: Sepolia only
- ChainId 11155111; active, well-supported explorers (Etherscan/Otterscan), robust faucet ecosystem. (chainid.network)
Validator/staking/protocol testing: Hoodi (replacing Holesky)
- Holesky sunset Sep 1, 2025. Hoodi is designed for validator lifecycle and protocol upgrades; do not rely on it for app testing. (blog.ethereum.org)
L2 testnets (mirror your mainnet L2 footprint)
- OP Sepolia, Arbitrum Sepolia, Base Sepolia, etc. Keep your L2 endpoints in lockstep with L1 Sepolia for consistent deposits/withdrawals and bridge flows. (ethereum.org)

Implementation note: Update your chain registry (e.g., Chainlist/chainid.network) and infra code with Sepolia and relevant L2-Sepolia chain IDs, explorers, and RPCs. (chainid.network)

2) RPC and vendor selection: evidence for Procurement

Requirements we prioritize:
- SOC2 or equivalent (Type II preferred), 99.99%+ uptime targets, global regions, rate-limit transparency, incident history.
Example attestations:
- Chainstack: SOC 2 Type II (Dec 2025), publicly highlighted alongside 99.99%+ uptime positioning. (chainstack.com)
- QuickNode: states SOC2 certification in enterprise positioning (Procurement will still request a report under NDA). (blog.quicknode.com)
Why this matters: “SOC2” becomes a gating keyword in RFPs, reduces security questionnaire cycles, and aligns with vendor risk policies. We handle the RFI/RFP prep and map controls to your MSA/SLA.

3) Faucets without drama

Preferred: Google Cloud Web3 Faucet (Sepolia) for predictable daily drips; supplement with Chainstack and QuickNode faucets as needed. (cloud.google.com)
Avoid social-only faucets for CI; use provider/API-keyed options to stabilize throughput. Ethereum.org maintains a current list of Sepolia faucets. (ethereum.org)
Operational guardrails:
- Budget test ETH demand; pre-warm project wallets weekly.
- Maintain an internal “faucet proxy” microservice with rate-limit backoff and retry policies.

4) DevSecOps: deterministic environments over public-testnet randomness

For reproducible, SOC2-aligned testing, augment Sepolia with:
- Mainnet-forked local chains for critical flows (Foundry/Anvil, Hardhat). Anvil/Foundry supports gas reporting to quantify regressions. (learnblockchain.cn)
- Virtual testnets (Tenderly Virtual TestNets) to eliminate faucet bottlenecks and share stable states across teams; supports Sepolia-based forks with “unlimited faucet” and state sync. (tenderly.co)

Why: You get Sepolia parity for integration tests, while performance, data-seeding, and edge cases run on forked/virtual networks that aren’t rate-limited by public infra.

5) Gas and cost realism in the Dencun era

L2 fees post-Dencun dropped ~90–98% (Base, OP Mainnet, Starknet), thanks to EIP-4844 blob pricing distinct from calldata. Your cost dashboards and alerts must reflect blob gas dynamics. (thedefiant.io)
What to change:
- Switch test networks to “-sepolia” L2s so your fee telemetry uses blob-backed batches.
- Use Foundry’s gas report in CI (forge test --gas-report) and snapshot diffs; integrate limits per PR to prevent regressions. (learnblockchain.cn)

6) Account Abstraction (EIP-4337) on Sepolia

If you use smart accounts, verify Entrypoint addresses per network. For Sepolia, common Entrypoint versions include:
- v0.6: 0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789
- v0.7: 0x0000000071727De22E5E9d8BAf0edAc6f37da032 (docs.pimlico.io)
Action items:
- Update bundler URLs to Sepolia equivalents (e.g., Pimlico/Stackup) and ensure paymasters fund test gas with clear limits in CI.
- Regenerate AA signing keys for test tenants; ensure KMS/HSM policy parity with production.

7) ZK workflows: run verifiers on Sepolia

Practical pattern:
- Prove off-chain (Halo2/Plonk or system-specific), verify on Sepolia with a deployed verifier contract, and simulate end-to-end flows on your target L2 Sepolia.
Why Sepolia now:
- It consistently tracks mainnet EVM behavior and upgrades (e.g., Dencun rolled through Goerli → Sepolia → Holesky before mainnet in 2024), keeping your verifier and calldata patterns relevant. (blog.ethereum.org)

Hands-on examples your team can lift-and-ship

Below are implementation snippets we standardize in Enterprise pipelines. They’re concise by design—drop into Makefiles or GitHub Actions to de-risk the migration.

A) One-time cutover: env, deploy, and verify on Sepolia

Network constants (validate once in CI):

# Confirm Sepolia chain id in CI to prevent network mismatches
cast chain-id --rpc-url "$SEPOLIA_RPC"  # expect 11155111

Foundry project config:

# foundry.toml
[profile.default]
src = 'src'
out = 'out'
libs = ['lib']
evm_version = 'cancun'
optimizer = true
optimizer_runs = 2_000

[rpc_endpoints]
sepolia = "${SEPOLIA_RPC}"

[etherscan]
sepolia = { key = "${ETHERSCAN_API_KEY}" }

# Gas visibility in CI
gas_reports = ["*"]

Deployment and verification:

# Deploy to Sepolia
forge create src/MyContract.sol:MyContract \
  --rpc-url "$SEPOLIA_RPC" \
  --private-key "$DEPLOYER_PK" \
  --verify --etherscan-api-key "$ETHERSCAN_API_KEY"

# Enforce gas ceilings per function via CI checks
forge test --gas-report | tee gas.txt
grep -E "MyContract\s+myHotPath\s+avg\s+([0-9]{1,6})" gas.txt \
  | awk '{ if ($4 > 90000) exit 1 }'

Why this matters: “gas ceilings” fail fast on performance regressions and keep budgets aligned with post-Dencun economics.

B) Fork mainnet for reproducible hot-path tests (no faucet wait)

# Use Anvil to fork mainnet for a reproducible test sandbox
anvil --fork-url "$MAINNET_RPC" --chain-id 1 --block-time 12 --steps-tracing
# In another shell, run:
forge test --fork-url "http://127.0.0.1:8545" --match-test testCriticalFlow --gas-report

This isolates performance-sensitive tests from public testnet variability while your integration flows still run on Sepolia.

C) Bridge ETH from Sepolia to OP Sepolia (Superchain)

Developer docs recommend bridging from Sepolia to OP Sepolia with the Superchain Bridges UI/SDK; CI tooling can call the same bridges for end-to-end tests. (docs.optimism.io)

Operational tip:

Stage deposits in a nightly job so your CI isn’t gated on bridge finality.

D) Account Abstraction (EIP-4337) quick-start on Sepolia

// Pseudocode: sponsor transactions via a paymaster on Sepolia
const entryPoint = "0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789"; // v0.6 on Sepolia
// assemble userOp, send to your bundler endpoint (Sepolia)

Confirm Entrypoint versions per your bundler provider to avoid mismatches during audits. (docs.pimlico.io)

Emerging best practices we apply on every Enterprise engagement

Separate concerns: Sepolia for app correctness; forks/virtual testnets for performance, data seeding, and chaos drills. Tenderly Virtual TestNets provide “unlimited faucet,” state sync, and private explorers—ideal for regulated teams who need controlled, auditable pre-prod lanes. (tenderly.co)
Validate upgrade cadence: Dencun hit Sepolia Jan 30, 2024 (epoch 132608) ahead of mainnet. Expect similar sequencing for future forks; wire alerting to EF testnet announcements. (blog.ethereum.org)
Treat faucets like dependencies: monitor status and rate limits; keep at least two alternatives (e.g., Google Cloud + Chainstack) to avoid CI stalls. (cloud.google.com)
L2 alignment: ensure your L2 testnets are the “-sepolia” variants (OP, Arbitrum, Base) to exercise blob-based fee paths and bridge logic that mirrors production. (alchemy.com)
Compliance by construction: shortlist SOC2-capable infra partners to shrink RFP cycles; where reports are gated (NDA), start request chains early. Chainstack’s SOC 2 Type II is a strong signal for procurement. (chainstack.com)

Prove: outcomes and GTM metrics tied to the migration

Time-to-Mainnet
- Consolidating pre-prod on Sepolia plus forked/virtual networks typically compresses UAT and regression cycles by removing faucet bottlenecks and Goerli breakage. In parallel, L2-sepolia bridges mirror production finality, reducing “last-mile surprises.”
Cost accuracy
- Post-Dencun blob economics are reflected on L2 Sepolia networks; moving test coverage there yields fee telemetry within a few percent of production trends. Public analyses show 90–98% L2 fee reductions post-Dencun—your unit-economics modeling should match that reality. (thedefiant.io)
Security and Procurement velocity
- Using vendors with SOC2 posture and published uptime simplifies vendor questionnaires and SLA negotiation. Chainstack publicly advertises SOC 2 Type II and 99.99%+ uptime positioning; QuickNode declares SOC2 certification. These claims don’t replace diligence, but they accelerate it. (chainstack.com)
Reliability of pipeline signals
- Combining Sepolia with Virtual TestNets (state sync, unlimited faucet) yields deterministic test data, faster defect isolation, and lower false negatives in CI—key to hitting quarterly release targets. (tenderly.co)

7Block Labs methodology: from RFP to production cutover

Architecture and network plan
- Map every workload to Sepolia/L2 Sepolia/Hoodi with explicit SLAs, explorers, and RPCs; codify in IaC and CI templates.
DevSecOps enablement
- Standardize Foundry/Hardhat stacks with gas reporting, mainnet forks, and deterministic data loads; add Virtual TestNets for team collaboration and perf tests without faucet limits. (learnblockchain.cn)
Compliance packaging
- Prepare SOC2-driven vendor packages for Procurement, including uptime/region attestations and incident handling playbooks. We align your internal controls with vendor artifacts to accelerate sign-off.
ZK and AA implementation
- Ship verifiers to Sepolia, bundle EIP-4337 flows against the correct Entrypoint versions, and exercise L2 blob fee paths on “-sepolia” networks. (docs.pimlico.io)
Cutover & KPI tracking
- Track: deploy lead time, defect escape rate, gas budget variance, faucet-induced test failures, and bridge failure MTTR. Tie improvements to ROI in your steering committee readouts.

Where we plug in:

Need end-to-end delivery? See our custom blockchain development services, web3 development services, and smart contract development.
Security and launch readiness? Use our security audit services to validate Sepolia/L2-sepolia deployments pre-mainnet.
Complex integrations and L2 bridges? We handle blockchain integration, cross-chain solutions development, and blockchain bridge development.
Full dApp stack? Explore our dApp development and DeFi development services.

Quick reference: current testnet landscape you can trust

Use Sepolia for application testing; chainId 11155111; explorer: sepolia.etherscan.io; permissioned validator set for stability. (ethereum.org)
Goerli is deprecated for application testing; major providers sunset RPCs as of Mar–Apr 2024. (alchemy.com)
Holesky deprecated Sep 1, 2025; Hoodi is the go-forward validator/staking testnet. Application developers should target Sepolia. (blog.ethereum.org)
L2s now standardize on Sepolia: OP Sepolia, Arbitrum Sepolia, Base Sepolia. Plan your bridge and fee tests accordingly. (docs.optimism.io)
Dencun (EIP-4844) activation timeline for testnets (2024): Goerli → Jan 17; Sepolia → Jan 30; Holesky → Feb 7. Mainnet followed in March 2024. (blog.ethereum.org)

Final word: make testnets a competitive advantage

Enterprise programs miss dates not because Solidity is hard, but because their pre-prod environment is fragile. The shift to Sepolia and Sepolia-based L2s is an opportunity: cleaner cost signals post-Dencun, saner faucets, better AA/ZK parity, and a clearer compliance story.

7Block Labs ships this as a package: SOC2-aware vendor selection, deterministic test stacks, and end-to-end contract + ZK + AA delivery tied to business KPIs.

Bold, measurable outcomes:

Faster release trains with fewer faucet-induced failures
Accurate gas forecasts in a blob-fee world
Shorter security and procurement cycles with SOC2-ready infra
Fewer late-stage surprises on bridges, AA, and ZK verifiers

Book a 90-Day Pilot Strategy Call.

References

EF: Holesky shutdown; use Sepolia for apps, Hoodi for validators. (blog.ethereum.org)
Ethereum.org: Networks—Sepolia default for app dev; Hoodi for validating/staking; L2 “-sepolia” testnets. (ethereum.org)
Goerli deprecation windows across ecosystems (Apr 1, 2024 for Ethereum; earlier for L2s). (alchemy.com)
EIP-4844 (Dencun) testnet dates and blob context; mainnet followed Mar 2024. (blog.ethereum.org)
Post-Dencun fee reductions on L2s (90–98%). (thedefiant.io)
Chain IDs and explorers (Sepolia 11155111; Hoodi info). (chainid.network)
Faucets: Google Cloud (Sepolia), Chainstack faucet guidance. (cloud.google.com)
AA Entrypoint addresses on Sepolia (reference values). (docs.pimlico.io)
Tenderly Virtual TestNets for deterministic environments. (tenderly.co)
SOC2 positioning: Chainstack Type II; QuickNode SOC2. (chainstack.com)