CertiK Alternatives: 10 Smart Contract Audit Firms Compared

By the Guardian team Updated November 2026 5 min read

Quick answer. The strongest CertiK alternatives, in Guardian's ranking: Guardian, Trail of Bits, OpenZeppelin, Spearbit, ChainSecurity, Zellic, Certora, Sigma Prime, Sherlock and Cyfrin. Choose by need: depth, a chain specialist, formal proofs or a contest.

Watch: CertiK Alternatives: 10 Smart Contract Audit Firms Compared 1:48

Video transcript

Looking beyond CertiK? The best alternative depends on your need: depth, a chain specialist, formal proofs or a contest.

CertiK counts 8,512 audits delivered, plus formal verification, pentesting and Skynet. So a switch is rarely about a missing service.

Teams often want a second audit, a specialist for ZK, consensus or Move code, a different model like contests, proofs at the core, or ongoing work after launch.

Guardian publishes this guide and ranks itself first. Next come Trail of Bits for tooling-heavy reviews, OpenZeppelin for code built on its library, Spearbit for elite researchers, and ChainSecurity for a Big Four affiliated auditor.

Zellic suits cryptography, ZK circuits, Solana and Move. Certora fits formal proofs, and Sigma Prime fits consensus code. Sherlock adds payout coverage to contests, and Cyfrin pairs a private audit with a competition.

Switching is a handover, not a restart. Check notice periods, hand over prior reports, freeze a commit, re-review what changed, and verify the deployment.

Guardian's track record: more than 300 Critical vulnerabilities reported, 45 billion dollars assessed, and more than 150 teams.

Vanguard puts two independent teams on one scope, and only human-verified findings reach the report. A hundred thousand dollar Defender contest, a bug bounty and six months of update review follow.

Read the full guide for every firm and the switching checklist, or get a second opinion from Guardian at guardian.security.

Disclosure: Guardian publishes this guide and ranked itself first, in the same order as our top smart contract auditors ranking. Claims about other firms, CertiK included, come from their own pages, public records or reputable reporting.

CertiK is one of the biggest names in Web3 auditing. Its homepage counts 8,512 audits delivered and 120,000+ findings reported.

Teams that look elsewhere often want something specific: a second opinion, a specialist, a different model or a wider scope.

This guide maps each alternative to that need.

Why Teams Look Beyond CertiK

First, what CertiK already offers, by its own pages:

Audits: manual review on every audit, plus AI tooling, in Solidity, Rust, Move, Vyper, Go and more.
Formal verification: an optional step against custom specifications.
Pentesting: 350+ pentests delivered, by its count.
Skynet: audited projects “earn a spot on the Skynet Leaderboard.”
CertiK Hunt: a researcher network for security challenges and bug bounties.

So a switch is rarely about a missing service. Common reasons to add or change a firm:

A second audit. Many protocols put more than one firm on the same code.
A specialist. ZK circuits, consensus clients, Solana or Move programs.
A different model. Contests, researcher networks, or two teams on one codebase.
Proofs. Formal verification as the core of the work, not an add-on.
After launch. Update review, contests and offchain pentests in one engagement.

Venus Protocol, a long-time CertiK client, shows the first pattern. One April 2024 governance proposal paid CertiK's and Quantstamp's retainers, plus Pessimistic and Fairyproof for audits of one upgrade.

None of this is a verdict on CertiK's work. CertiK ranks fourth in our guide to the best web3 pentesting firms.

Comparison at a Glance

#	Firm	Model	Choose it for
1	Guardian	Two-team audits, AI auditor, offchain pentesting	Every surface, before and after launch
2	Trail of Bits	Private audits and security engineering	Tooling-heavy reviews across many chains
3	OpenZeppelin	Private audits and open-source libraries	Code built on OpenZeppelin Contracts
4	Spearbit (Cantina)	Network of independent researchers	Reviewers from an elite researcher network
5	ChainSecurity	Private audits; team joined PwC Switzerland	A Big Four affiliated auditor
6	Zellic	Private audits and research	Cryptography, ZK circuits, Solana and Move
7	Certora	Formal verification	Proofs of critical properties
8	Sigma Prime	Audits and protocol research	Consensus, L1 and L2 protocol code
9	Sherlock	Contests, private audits, coverage	A contest with exploit payout coverage
10	Cyfrin	Private audits and CodeHawks competitions	A private audit plus a competition

The 10 Alternatives by Need

1. Guardian

Choose it for: every surface covered, onchain and offchain, before and after launch
Track record: 300+ Critical vulnerabilities reported, $45B assessed, 150+ teams

Two independent teams review the same codebase, then a contest, a bug bounty and update review follow. Details are below.

2. Trail of Bits

Choose it for: tooling-heavy reviews of full systems, across many chains
Known for: Slither, Echidna and Medusa, the tools it says much of the industry audits with

Its reviews cover contracts, nodes, bridges and governance on EVM, Move, Solana, Cosmos, Starknet and more.

3. OpenZeppelin

Choose it for: code built on OpenZeppelin Contracts, the library it introduced in 2015
Track record: 900+ audits since 2017, by its count

It says each line of code is inspected by at least two security researchers.

4. Spearbit (Cantina)

Choose it for: reviewers drawn from a network of elite independent researchers
Known for: the network behind Cantina's audits, competitions and bug bounties

Cantina says it “grew out of the Spearbit network of elite security researchers.”

5. ChainSecurity

Choose it for: institutions that want a Big Four affiliated auditor
Background: an ETH Zurich spin-off founded in 2017; its team joined PwC Switzerland in 2020

6. Zellic

Choose it for: applied cryptography, ZK circuits, Solana and Move chains such as Aptos and Sui
Track record: 338 reviews in 2025, 153 with critical or high-impact findings, by its count

7. Certora

Choose it for: proving that critical rules hold in every contract state
Known for: the Certora Prover, open-sourced in February 2025, for Ethereum, Solana and Stellar

A proof is only as strong as its specification, so pair it with manual review.

8. Sigma Prime

Choose it for: consensus, networking, bridge and sequencing code on L1s and L2s
Known for: Lighthouse, “one of five production consensus clients on Ethereum”

9. Sherlock

Choose it for: a contest with payout coverage for qualified audited code
Known for: contests, private audits, bug bounties and Sherlock Shield

Sherlock describes Shield as “exploit payout coverage for qualified audited code.”

10. Cyfrin

Choose it for: a private audit alongside a CodeHawks competition
Known for: Solodit, its exploit and mitigation database, and the Aderyn Solidity analyzer

Also consider: OtterSec, for Solana and Sui programs. It counts 120+ projects audited.

On price: CertiK publishes no rate card. See CertiK audit cost for its public records, and what top auditors charge for other firms.

How to Switch Mid-Roadmap

Switching is a handover, not a restart.

Check your terms. Retainers carry notice periods. CertiK's Venus terms allow exit on 10 business days' written notice, effective the next month.
Hand over every report. Give the new firm prior findings and their fix status.
Freeze a commit. Scope by commit hash, and flag what changed since the last audit.
Re-review what changed. New modules get a full review. See when you need a re-audit.
Get a start date in writing. CertiK's Venus terms set starts within 7 or 14 business days.
Publish the new report. Skynet's score draws on “all publicly available audit reports from established security providers.”
Verify the deployment. Check that deployed bytecode matches the audited commit.

How Guardian Audits

Vanguard, Guardian's flagship audit, is built for teams that want more than one review of the same code.

Two independent teams on one scope: manual review with invariant fuzzing, and Helix, Guardian's AI auditor.
Only human-verified findings enter the final report.
A $100,000 Guardian-funded Defender contest on the audited scope.
A hosted bug bounty with $50,000 in Critical matching.
Half the package cost back as credits toward offchain assessments.
Six months of update review: up to 2,500 onchain or 10,000 offchain SLOC.

Guardian's reports are public in the audit portfolio. Teams can also apply for the Guardian Security Fund, which offers $1,000,000 in audit grants.

Frequently Asked Questions

What are the best alternatives to CertiK?

Against the criteria in this guide, which Guardian publishes, Guardian ranks first, then Trail of Bits, OpenZeppelin and Spearbit. Zellic, Certora and Sigma Prime suit specialist code; Sherlock and Cyfrin add competitions.

Is CertiK a good auditor?

CertiK is one of the largest firms by volume, with 8,512 audits delivered by its count, plus formal verification, pentests and Skynet. Fit depends on your code and chain, so read its public reports on protocols like yours.

Can I use CertiK and another auditor?

Yes. Many protocols use more than one firm. Venus, a long-time CertiK client, paid CertiK's and Quantstamp's retainers, plus two firms' audits of one upgrade, in one April 2024 governance proposal.

How much does CertiK charge?

CertiK publishes no prices. Its 2024 renewal proposal to Venus set $420,000 for 24 months: 50 hours a month at $350 an hour. Single-audit quotes follow a scoping step, and CertiK says onboarding varies with code size.

Sources

Get a second opinion from Guardian

Vanguard puts two independent teams on your code, then keeps reviewing every update for six months.

Get a quote Explore Vanguard