Codex

Why it ranks #1

Codex, an AI software engineer by OpenAI, ranks #1 of 999 AI agents and #1 of 40 in Software engineer, with a score of 9.7 of 10. Data as of 3 Oct 2026.

The score adds four parts, each 0 to 10, by weight. Every point comes from public evidence. How scoring works · Score wrong? Suggest a change

1. Proof

   Do customers use it? 30% of the score

   10

   Claims revenue or growth, named customers, a customer result and a customer count.

   • +4
     Revenue or growth

     “Weekly Codex users have more than tripled since the start of the year to 1.6M.”

     Source · 27 Feb 2026
   • +3
     Named customers

     ““At Wonderful, Codex CLI has completely replaced every other agentic harness for our core technology and architecture work requiring deep reasoning and understanding.””

     Source
   • +2
     A customer result

     ““At Harvey, Codex transformed how we build by cutting early iteration time by 30–50%, freeing engineers to focus on system design and high-leverage decisions.””

     Source
   • +2
     A customer count

     “OpenAI said Codex has more than 5 million weekly active users with knowledge workers representing 20% of users and growing rapidly.”

     Source · 2 Jun 2026

   Not found: work done at scale (+2)

2. Scale

   Is there a real company behind it? 30% of the score

   10

   4500 people, raised $122B.

   • +7
     4500 people at OpenAI100 or more people
   • +3
     Raised $122BOpenAI raises $122 billion at $852 billion valuation, closing largest funding round in historySource · 31 Mar 2026

3. Momentum

   Is it shipping and growing now? 25% of the score

   10

   Shows a recent launch, hiring, a new claim and funding news.

   • +3
     Release post in the last 6 monthsCodex CLI 0.160.0Source · 1 Oct 2026
   • +3
     Hiring: 823 open rolesTechnical Program Manager, Compute Infrastructure, Research Engineer, Account Director, Large Enterprise - TokyoSource
   • +2
     A new traction claim

     “OpenAI said Codex has more than 5 million weekly active users with knowledge workers representing 20% of users and growing rapidly.”

     Source · 2 Jun 2026
   • +2
     Funding news in the last yearOpenAI raises $122 billion at $852 billion valuation, closing largest funding round in historySource · 31 Mar 2026

   Not found: founded in the last year (it was founded in 2015) (+1)

4. Autonomy

   How much of the job does it do on its own? 15% of the score

   8

   Autonomous worker: completes whole tasks; people handle exceptions.

   • +8
     Level 3 of 4: Autonomous workerCompletes whole tasks; people handle exceptions.
   How the level was set

   • Level 3 (autonomous worker) from a reviewed decision that cites the product's own pages

   Level 3: Completes whole tasks; people handle exceptions.

About Codex

Launches and news

1. Release1 Oct 2026Codex CLI 0.160.0
2. Release19 Aug 2026GitLab support in Codex cloud (Beta)
3. Release4 Mar 2026The Codex app is now available on Windows
4. Release2 Feb 2026Introducing the Codex app

Alternatives in Software engineer

The top Software engineer agents by score, with Codex in its place.

1. 1CodexSoftware engineerby OpenAIThe best way to build with agents. Codex accelerates real engineering work, from planning and building features to refactors, reviews, and releases.Proof10Scale10Momentum10Autonomy8Score9.7
2. 2Claude CodeSoftware engineerby AnthropicAnthropic's agentic coding tool for developers.Proof10Scale10Momentum10Autonomy8Score9.7
3. 3CursorSoftware engineerby AnysphereCursor is your coding agent for building ambitious software.Proof10Scale10Momentum10Autonomy8Score9.7
4. 4Factory DroidsSoftware engineerby FactoryFactory Droids automate coding, testing, and deployment for startups and enterprises.Proof10Scale3Momentum10Autonomy8Score7.6
5. 5DevinSoftware engineerby CognitionCognition operates Devin, the first autonomous software engineer.Proof7Scale3Momentum10Autonomy8Score6.7
6. 6Copilot cloud agentSoftware engineerby GitHubGitHub Copilot works every step of the way, from an open issue to reviewing and merging a pull request.Proof0Scale10Momentum3Autonomy8Score5.0

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