Code Audits
Solidity Audit
Prevent exploits before they reach users. Our Solidity smart contract audits find real risks and give you a prioritized report with issues, severity, and fixes. Our specialized Solidity auditors perform in-depth reviews using static analysis, manual inspection, and custom threat modeling to help you ship code that’s safe, efficient, and mainnet-ready.
150+
audits
completed
$10B+
in client
assets protected
$200B+
in transacted
value secured
300+
crit / high issues found
Consolidated clients
A Web3 security company with
3+ years of experience
Whether you are building a DeFi platform, compliance solutions, or an on-chain game, we tailor the review to your architecture and integrations so findings mirror real risk and changes are easy to merge.
What is a Solidity Audit?
A solidity smart contract audit is a comprehensive review of smart contracts built for the Ethereum Virtual Machine (EVM). It verifies that your contract logic works as intended and helps prevent vulnerabilities that could be exploited post-deployment. At Three Sigma, our Solidity audits go beyond automated checks. We manually analyze business logic, token integrations, access control, and upgrade patterns. For broader coverage, we also offer Dapp Audits and OpSec audits.
What You Get from Our Solidity Audits
Every Solidity audit we do is about client-driven outcomes. You get an audit report that prioritizes issues by severity, explains the risk, and recommends the smallest safe change to fix it. Afterward, we review your pull requests, retest the fixes, and provide a clear final status you can share with stakeholders. If you are comparing partners, see our guide on picking the right blockchain auditor.
Common Vulnerabilities Found in Solidity Audits
Reentrancy and unsafe external calls
Reentrancy across functions, contracts, or via callbacks (including read-only reentrancy) when contracts call external addresses before updating state.
Protocol-specific logic flaws
Intended rules break under edge cases, so valid-looking transactions cause harmful outcomes (e.g., bad fee math or incorrect liquidations).
Validation and signature bugs
Weak input checks or signature validation mistakes (EIP-712, EIP-2612) enable replay attacks, spoofed approvals, or bypassed limits.
Access control errors
Misused roles, tx.origin checks, or upgrade keys let unauthorized actors execute privileged actions or swap implementations.
Year after year, attackers exploit smart contracts via the same recurring patterns, the issues below are specific to Solidity and the EVM and show up repeatedly in real audits.
Our Solidity Audit Process
Scoping and planning
We define the full Solidity audit scope, list contracts, libraries, proxies, dependencies, and critical entry points, and align on objectives and timelines.
Architecture review
We examine protocol design and integrations, map attack surfaces, and flag systemic risks in roles, permissions, upgrade patterns, token flows, and oracle interactions.
Code review
We perform a line-by-line Solidity security review to detect vulnerabilities, gas pitfalls, and deviations from best practices, including storage layout, initialization, and upgrade safety.
Testing
We run static analysis, write property tests, apply targeted fuzzing, and use mainnet-fork or testnet simulations. We build proofs of concept to reproduce issues and measure real impact.
Reporting and recommendations
You receive a full audit report with prioritized findings and step-by-step remediation guidance.
Verification
After fixes, we retest on the patched release and confirm that issues are resolved before mainnet deployment.
Benefits of a Solidity Audit with Three Sigma?
Risk-first coverage that mirrors real attack paths.
A Solidity audit should follow money and permissions. We map trust boundaries, roles, and upgrade hooks, then probe reentrancy, oracle reads, liquidity flows, and MEV in realistic scenarios. You get a ranked remediation plan that collapses whole exploit classes early and fits your roadmap.
Actionable findings with minimal-change fixes.
Every issue ships with severity, impact, repro steps, and the smallest safe patch, whether code, config, or process. We add safe patterns and test hints so fixes land fast. “Quick wins” unlock momentum; structural risks come with clear acceptance criteria.
Verification that stakeholders can trust.
We don’t stop at a PDF. After fixes, we retest, review PRs, and issue a concise final status. Partners and listings can parse it at a glance; engineers get exact code-level changes; executives get a clean risk ledger for your smart contract audit.
Enduring improvements to code quality and speed.
A good audit clarifies invariants, tightens interfaces, and makes assumptions explicit. We leave preventative tests (assertions, property checks, differentials) so regressions stay out. Teams ship to mainnet with fewer surprises and keep velocity.
Our Solidity Audit Services
Three Sigma’s solidity contract audit services cover
Ethereum & all major EVM networks
Arbitrum
Polygon
Base
Linea
Optimism
Avalanche
BNB Chain
Scroll
Whether you are launching a new smart contract or reinforcing an existing deployment, our Solidity audit services adapt to your architecture and secure your code before it reaches mainnet. If you are building on another stack like Solana or NEAR, our experienced Rust auditors can review your code with the same depth and rigor.
Why Choose Three Sigma?
Outcome over optics
We optimize exploit risk reduction and low-friction fixes, not vanity issue counts. Reviews are sequenced by economic impact and reachability so early patches do the most good. Measure success by safe launches, smooth upgrades, and faster integrations. No security theater, just progress you can point to.
A process that respects developer time.
We sync early on risky flows and keep comms jargon-light. Findings ship with suggested diffs and test hints so patches land quickly. Depth matches risk: deep where loss is catastrophic, light where it’s bounded. Your smart contract audit fits how your team actually ships software.
Senior, attacker-minded reviewers.
Your Solidity audit is led by engineers who’ve built, and broken, complex on-chain systems. We think like adversaries and write like teammates: architecture-specific threat models, pragmatic trade-offs (gas vs. safety, UX vs. controls), and refactor guidance with migration steps and measurable acceptance criteria.
Proof, closure, and ongoing support.
We verify remediation with PR reviews and targeted retests, then issue a concise, shareable status for partners, listings, and integrations. Post-audit, we’re available to sanity-check upgrades, triage late discoveries, or review emergency patches, turning findings into durable improvements in how you design, test, and ship.
Hear from our Clients
Deliverables You Can Expect
Each Solidity audit report outlines the vulnerabilities we found, their severity, affected components, and clear remediation steps
Post-audit support is included
to help your team implement fixes and validate the results.
These deliverables are not a security stamp, they provide technical clarity, tangible security improvements, and stakeholder-ready documentation you can share with investors, partners, or listings. See our case studies for a sample of what that looks like.
What You Gain
from a Three Sigma Audit
Our Solidity audit reduces risk at go-live and aligns your code with best practices.
Prevent costly exploits before they impact your users.
Increase trust with investors, partners and the Web3 community.
An audit can help streamline approvals for listings, integrations, and reviews.
Protect brand reputation and reduce time to recovery.
Industries We Secure
Our audits have helped secure decentralized applications across multiple verticals.
DeFi &
Liquidity
Lending platforms, DEXes, staking, and collateral markets.
NFT &
Collectibles
Marketplaces, launchpads, minting tools, and creator hubs.
Gaming &
Metaverse
Play-to-earn games, trading hubs, and immersive 3D worlds.
Cross-Chain Infrastructure
Bridges, oracle networks, and cross-chain protocol layers.
Frequently Asked Questions
Check out the Solidity Audits F.A.Q.
What does a Solidity audit focus on?
We assess logic and economic correctness, roles and permissions, upgrade paths, error handling, integrations, and environment behaviors that affect safety.
What tools are used in Solidity audits?
We pair manual code review with static analyzers, fuzzing, and mainnet-fork testing. Tools support the work; they do not replace it.
How often should Solidity contracts be audited?
Before deployment, after major upgrades, and when ecosystem incidents affect your dependencies.
Can a Solidity audit detect gas inefficiencies?
Yes. We highlight costly loops, storage patterns, and execution paths and suggest safer, cheaper alternatives.
How do Solidity audits prevent reentrancy attacks?
By analyzing execution order and external calls and enforcing the checks–effects–interactions pattern with proper guards.