How Big Are Smart Contract Audit Firms in 2026?
Quick answer. Most are small. Of nine audit firms tracked on LinkedIn, only CertiK tops 200 people, and only OpenZeppelin and Trail of Bits top 100. The seven with early 2024 data grew 8% combined in almost three years.
Video transcript
Most smart contract audit firms are small. Of nine firms we tracked on LinkedIn, only CertiK tops two hundred people.
Using archived LinkedIn pages, the seven firms with early 2024 data grew just eight percent combined in almost three years. Guardian competes with them all, so we left ourselves out.
Most big firms barely moved. CertiK stayed near two hundred, Trail of Bits ended where it started, and OpenZeppelin grew most. Quantstamp shrank by forty two percent.
The fastest growth came from small teams. Zellic doubled, Cyfrin grew eighty percent, and OtterSec and ChainSecurity also grew. A few hires move a small team's numbers a lot.
LinkedIn can mislead. Cantina's page shows three hundred eight people, but many are likely network researchers, not staff. Consensys Diligence lists just eleven.
Size says little about your audit. Ask who exactly is on your audit, how many review the full scope, what AI reviews and who verifies it, and who reviews changes after launch.
More reviewers on one pass tend to share blind spots. Guardian puts two independent teams on one scope: manual review with invariant fuzzing, and Helix, our AI auditor. Only human-verified findings reach the report.
Read the full article for every firm's numbers, or talk to Guardian about an audit at guardian.security.
Audit firms rarely publish their headcount. Buyers ask anyway, because size hints at how soon a firm can start and who will read the code.
So we counted. We read archived copies of each firm's public LinkedIn page, month by month, through November 2026.
Most of the big firms are about the size they were in early 2024. The fastest growth came from smaller teams and from a network of freelance researchers.
How We Counted
The measure. Headcount here means LinkedIn members: people whose profile lists the firm as their current employer. LinkedIn shows that count on every company page.
The source. The Internet Archive has saved those pages over time. We read the count from one capture per month, wherever one exists.
LinkedIn blocked the archive's crawler before 2024, so most series start then. For Quantstamp we added three LinkedIn readings recorded by Latka.
The firms. We started from our top 10 smart contract auditors and added CertiK, Halborn, Quantstamp, OtterSec and Consensys Diligence.
Three firms from that list, Certora, Sigma Prime and Sherlock, had no archived LinkedIn pages we could find. That left eleven.
Cantina and Consensys Diligence have pages that don't match their staff, so they get a section of their own.
Limits. LinkedIn is not payroll. It misses staff who aren't on LinkedIn, counts some contractors and includes non-audit teams. It is still the one measure every firm shares.
Guardian competes with every firm here, so we left ourselves out. Every reading links to its archived page in the data file (CSV).
Headcount by Firm
Nine firms have LinkedIn pages that track their staff. Each panel below has its own scale.
| Firm | First reading since 2024 | Latest reading | Change |
|---|---|---|---|
| CertiK | 203 (Jan 2024) | 208 (Oct 2026) | +2% |
| OpenZeppelin | 91 (Jan 2024) | 124 (Nov 2026) | +36% |
| Trail of Bits | 106 (Jan 2024) | 106 (Nov 2026) | 0% |
| Halborn | 67 (Jan 2024) | 75 (Aug 2026) | +12% |
| Quantstamp | 90 (Jan 2024) | 52 (Oct 2026) | −42% |
| Zellic | 23 (Feb 2024) | 46 (Oct 2026) | +100% |
| OtterSec | 32 (Oct 2024) | 46 (Oct 2026) | +44% |
| Cyfrin | 20 (Jan 2024) | 36 (Jul 2026) | +80% |
| ChainSecurity | 23 (Apr 2024) | 30 (Sep 2026) | +30% |
Seven firms have readings from January or February 2024. Together they went from 600 to 647 people, up 8% in almost three years.
Mostly Steady at the Top
CertiK is the largest by a wide margin. Its count peaked at 247 in April 2023 and fell to 211 by December.
In October 2023, CEO Ronghui Gu told ForkLog that layoffs affected less than 15% of staff. Since 2024, CertiK has stayed between 184 and 213.
Trail of Bits fell from 106 to 86 in early 2025, then grew back to 106. Its count covers the whole firm, which also works outside blockchain.
OpenZeppelin grew the most of the large firms, from 91 to 124. Its count includes the team behind the OpenZeppelin Contracts library.
Halborn rose from 67 to 86 by mid-2025, then eased to 75 in August 2026.
Small Teams Grew Fastest
Zellic doubled, from 23 people in February 2024 to 46 in October 2026. Cyfrin grew from 20 to 36 between January 2024 and July 2026.
OtterSec grew from 32 to 46 in the two years from October 2024. ChainSecurity went from 23 to 30 between April 2024 and September 2026.
A few hires move a small team's numbers a lot. Zellic's doubling took 23 people, fewer than OpenZeppelin added over the same period.
One Firm Shrank
Quantstamp is the exception. Its count fell from 93 in October 2023 to 52 in October 2026, down 44%.
Latka recorded 84 in December 2022, so the 2023 high followed a year of growth. We found no public report of layoffs. The captures show a steady decline over three years.
When LinkedIn Misleads
Two firms show why a headcount needs context.
Cantina. Its page grew from 101 people in July 2025 to 308 in October 2026. Cantina grew out of Spearbit's network of independent security researchers.
Until mid-2026, the same page gave Cantina's own size as 11 to 50 employees. So many of those 308 are likely network researchers, not staff.
Consensys Diligence. Its page lists just 11 people. Diligence is a unit of Consensys, and many of its staff likely list the parent company instead.
Consensys cut about 160 of its 828 employees in October 2024, Fortune reported. The report did not break out Diligence.
Outside estimates disagree too. Revelio Labs' model put Halborn at 103 in mid-2026, when LinkedIn showed 78.
What to Ask Instead
A firm's size says little about your audit. What matters is who reads your code, and how much of it each person covers.
Ask every firm:
- Who exactly is on my audit, and what have they found before?
- How many people review the full scope, and do they work independently?
- What does AI review, and who verifies its findings?
- Who reviews my changes after launch?
Our guide to choosing a smart contract auditor turns these into a scorecard. For what the same firms charge, see audit firm pricing compared.
Coverage, Not Headcount
Adding reviewers to one pass does not add coverage. Reviewers who share a pass tend to share blind spots.
A Guardian smart contract audit puts two independent teams on one scope. Team A pairs expert manual review with an invariant fuzzing suite.
Team B runs Helix, Guardian's AI auditor: hundreds of parallel agents across the whole codebase. Only human-verified findings reach the report.
The fuzzing suite stays with you, so every later change is tested against the same invariants.
Frequently Asked Questions
Which smart contract audit firm has the most employees?
CertiK, with 208 people on LinkedIn in October 2026, about 70% more than OpenZeppelin. Cantina's page shows 308, but Cantina gives its own size as 51 to 200 employees, so many of those people are researchers in its network.
How many people work at Trail of Bits?
106 people listed Trail of Bits on LinkedIn in November 2026. Its team page names 91, including 63 in engineering, and calls them "a public subset of the full team." Both cover the whole firm, not only blockchain work.
Is a bigger audit firm better?
Not on its own. Your audit is done by the few people assigned to it, not by the whole firm. Compare the named reviewers, how much of the scope each one covers, and whether fix reviews are included.
Sources
- Internet Archive: CertiK LinkedIn page, captured October 2, 2026
- Internet Archive: OpenZeppelin LinkedIn page, captured November 1, 2026
- Internet Archive: Trail of Bits LinkedIn page, captured November 2, 2026
- Internet Archive: Halborn LinkedIn page, captured August 18, 2026
- Internet Archive: Quantstamp LinkedIn page, captured October 6, 2026
- Internet Archive: Zellic LinkedIn page, captured October 13, 2026
- Internet Archive: OtterSec LinkedIn page, captured October 5, 2026
- Internet Archive: Cyfrin LinkedIn page, captured July 4, 2026
- Internet Archive: ChainSecurity LinkedIn page, captured September 2, 2026
- Internet Archive: Cantina LinkedIn page, captured October 11, 2026
- Internet Archive: Consensys Diligence LinkedIn page, captured October 5, 2026
- Latka: Quantstamp headcount readings (accessed November 10, 2026)
- Revelio Labs: Halborn employee count by quarter (accessed November 10, 2026)
- ForkLog: CertiK to reduce headcount amid market dynamics (October 13, 2023)
- Fortune: Ethereum giant Consensys slashes workforce by 20% (October 29, 2024)
- Cantina: About Cantina, documentation (accessed November 10, 2026)
- Trail of Bits: Team page (accessed November 10, 2026)
- Guardian: Audit firm headcount data, every reading with its source (CSV)
Two teams on your code, not one
Guardian puts manual review with fuzzing and the Helix AI auditor on the same scope, independently.