Best Smart Contract Auditing Companies

There are over a hundred crypto smart contract auditing companies, most charging thousands of dollars for reports aimed at uncovering vulnerabilities and improving security. Since most startups can only start with one, this is an important and difficult decision.

As founders and developers, it’s crucial to find the best option by considering factors like cost, expertise, tools, and client feedback. We leveraged our Web3 connections, spoke with leading projects, and gathered their firsthand experiences with crypto auditors.

Based on this research, we’ve compiled a list of the top 5 smart contract auditing companies, summarized in the table below for your convenience.

1. CertiK

CertiK is a trusted name for crypto project founders seeking airtight smart contract security. With a rigorous three-layer review process, CertiK identifies vulnerabilities early, ensuring your code is launch-ready. So far, they have secured over $422B in value, the most of any crypto auditing platform.

Their audits aren't solely about spotting flaws, they provide actionable insights to help you strengthen your smart contracts for the long term. CertiK’s expertise spans thousands of projects, delivering a proven track record that builds confidence for founders building Web3 applications.

In 2024, CertiK faced criticism over its handling of a vulnerability report to Kraken, leading to a public dispute, but the company has since taken steps to refine its processes and rebuild trust. If you need fast, precise, and reliable audits, CertiK’s blend of AI-driven and manual review processes has you covered.

• Supported Blockchains: BNB Chain, Ethereum, Avalanche, Solana, Algorand, Near, Cosmos.
• Services: Smart Contract Audit, Penetration Testing, Formal Verification, KYC, Bug Bounty, Skynet, Skytrace, Sky Harbor, and Advisory Services.
• Major Clients: Aptos, Gala Games, BNB Chain, Tether, XRP, Shiba Inu, Polygon, Frax.
• Hacked Clients: Gala Games ($216M), Woofi ($85M), ZKasino ($33M), Arbix Finance ($10M), Onyx Protocol ($3.8M), Merlin DEX ($1.8M), Saddle Finance ($275K).

2. Hacken

If you are looking for a security partner that combines technical expertise with community-driven innovation, Hacken offers a compelling choice. Their signature "DualDefense" system ensures your smart contract undergoes not only a professional audit but also an additional crowdsourced review by thousands of white-hat hackers.

For founders, this means unmatched protection with two layers of scrutiny, all included in the same service package. Hacken’s history is not without challenges, including losses from flash loan exploits on Warp Finance and Merlin Labs totaling $8.5M, but these incidents led to crucial upgrades in their audit methodology.

They have since become a trusted name in Web3 security, helping founders avoid vulnerabilities that can erode user trust. With Hacken, you don’t just get an audit you gain a transparent, collaborative process that reflects your commitment to safety and responsibility.

• Supported Blockchains: Ethereum, BNB Chain, Polygon, Optimism, Solana, Near, Aptos.
• Services: Smart Contract Audit, Blockchain Protocol Audit, DApp Audit, Penetration Testing, Bug Bounty, Proof of Reserves, CCSS Audit, Tokenomics Audit.
• Major Clients: NEAR, WhiteBIT, VeChain, KuCoin, Sandbox, CIVIC, Enjin, Kyber Network, UniCrypt, and others.
• Hacked Clients: Warp Finance ($7.8M), Merlin Labs ($680K), Velocore ($6.8M).

3. OpenZeppelin

If automation is your priority, OpenZeppelin is the clear choice for securing and managing your smart contracts. Their "Defender" platform is one-of-a-kind, offering tools to automate smart contract operations, monitor transactions, and manage private infrastructure securely.

This allows founders to automate development workflows while ensuring solid security measures are in place. OpenZeppelin also provides a transparent audit process with clear deliverables, making it easy to track vulnerabilities and implement fixes efficiently.

Their expertise in developing the open-source OpenZeppelin Contracts has made them a cornerstone of blockchain development, allowing teams to build on secure and battle-tested foundations. With OpenZeppelin, you gain a long-term partner in automating and safeguarding your Web3 project.

• Supported Blockchains: Ethereum, Layer 2s and other EVM chains.
• Services: Smart Contract Audits, Automated Ethereum Operations, Security Audits for Distributed Systems, OpenZeppelin Defender, OpenZeppelin Contracts.
• Major Clients: Ethereum Foundation, Brave, Optimism, Coinbase, Compound, BitGo, AAVE, The Graph.
• Hacked Clients: Audius ($6M), Saddle Finance ($275K).

4. Quantstamp

Quantstamp delivers unmatched expertise for founders who need full security and peace of mind for their blockchain projects. Their approach goes beyond traditional audits, offering regulated smart contract insurance through their Chainproof platform to protect projects against unforeseen exploits.

For founders, this means not only securing your code but also safeguarding your assets with institutional-grade coverage. Quantstamp’s team, composed of veterans from companies like Google, Ethereum Foundation, and Meta, excels in tackling complex security challenges across 40 blockchains.

While high-profile breaches such as the Alpha Finance hack revealed gaps in the past, Quantstamp has continuously refined its methodologies to address evolving risks. With over 750 audits completed and $200B in secured digital assets, Quantstamp stands out as a lasting auditing partner.

• Supported Blockchains: Ethereum, Solana, Flow, Binance Chain, Avalanche, and more.
• Services: Smart contract audits, Layer 1 blockchain reviews, NFT and DeFi application security, Chainproof (regulated smart contract insurance).
• Major Clients: Ethereum, Binance, Solana, Polkadot, Arbitrum, OpenSea and more.
• Hacked Clients: Alpha Finance ($37.5M), Rari Capital ($10M), Saddle Finance ($275K).

5. Trail of Bits

Trail of Bits brings over a decade of cybersecurity expertise, blending its Web 2.0 roots with a forward-thinking approach to blockchain security. Established in 2012, the company has evolved to secure leading blockchain projects like Ethereum, Uniswap, and MakerDAO.

Their in-house tools, such as Slither and Echidna, are considered gold standards for identifying vulnerabilities in smart contracts and other blockchain components. For early-stage projects, Trail of Bits offers design and architecture reviews to embed security into the foundation, minimizing future risks.

They also tackle complex issues like cryptographic validation and cross-chain vulnerabilities, providing actionable insights tailored to your needs. Trail of Bits stands out as a trusted partner for founders seeking rigorous security combined with innovation.

• Supported Blockchains: Various, including Ethereum.
• Services: Software Assurance, Security Engineering, Research & Development, Mobile Device Security (iVerify), Open Source Tools.
• Major Clients: Airbnb, Lido, Facebook, Google, Microsoft, Zoom, Reddit, Stripe.
• Hacked Clients: Raft ($3.3M), Saddle Finance ($275K).
  

What is a Smart Contract Audit?

A smart contract audit is a thorough examination of the contract’s code to uncover vulnerabilities, inefficiencies, and potential exploits. Auditors analyze the logic, architecture, and dependencies of the code, ensuring it functions securely and as intended within its blockchain ecosystem.

The process helps blockchain projects mitigate risks by identifying security flaws before deployment. Smart contract audits are essential for protecting assets, building user trust, and ensuring the long-term reliability of decentralized applications.

How to Audit a Smart Contract

Auditing a smart contract requires expertise in blockchain technology, knowledge of programming languages like Solidity, and access to specialized tools such as Slither, Echidna, and MythX.

It is typically performed by professional auditing firms that follow a structured process to identify vulnerabilities and ensure the contract operates securely:

1. Understanding the Contract: Analyze the intended functionality and design of the smart contract.
2. Code Review: Conduct a line-by-line analysis to find vulnerabilities or logic errors.
3. Static Analysis: Use automated tools to scan for common vulnerabilities and inefficiencies.
4. Dynamic Testing: Simulate real-world scenarios to stress test the contract’s behavior.
5. Formal Verification: Mathematically verify critical functions to ensure correctness.
6. Report Generation: Document findings, assign severity ratings, and suggest remediation steps.
7. Review Fixes: Retest the code after updates to confirm all vulnerabilities are resolved.

When choosing a smart contract auditor, look for firms that follow this process and offer added protections, such as insurance guarantees or detailed post-audit support.

How Much Does a Smart Contract Audit Cost?

The cost of a smart contract audit typically ranges from $5,000 to $15,000 for straightforward projects. However, more complex contracts or those requiring advanced testing, such as formal verification, can cost upwards of $100,000. Pricing varies based on factors like contract size, complexity, and the reputation of the auditing firm.

How Long Does It Take to Audit a Smart Contract?

The time required for a smart contract audit depends largely on the project’s size and complexity. Simple contracts, like tokens, can be audited in a few days, while more complex applications with intricate tokenomics may take a week or more. Advanced audits that involve thorough manual reviews and backdoor detection can extend to several weeks, up to a month.

Additional factors include whether the audit is manual or automated and if interim reports are requested. Manual reviews, though time-intensive, provide deeper insights and reduce false positives, while automated scans with smart contract auditing tools like Mythril or Slither offer faster but less exhaustive results.

Bottom Line

To date, over $9.06 billion has been lost to crypto hacks, making security an absolute necessity for any blockchain project. If you’re launching a crypto project, partnering with a top-tier auditing firm is essential to safeguard your assets and reputation.

In 2024, the five best auditors are CertiK, Hacken, OpenZeppelin, Quantstamp, and Trail of Bits which stand out for their expertise, innovative tools, and commitment to continuous improvement.

While some have faced challenges in the past, each has taken proactive steps to refine their methodologies and rebuild trust, making them reliable partners for securing your Web3 venture.