Two years ago, AI for coding was mostly autocomplete: you typed a line and it suggested the next one. In 2026, the norm is to hand it an entire task, such as fixing a bug or adding a feature along with its tests, and let an agent read the project, modify the files and run whatever commands are needed.

Three tools dominate that conversation: Claude Code, from Anthropic; Codex, from OpenAI; and Cursor. I use them in my daily work, and in this article I explain what each one does, what it costs, how they genuinely differ and what the research says about whether they really speed things up.

What a coding agent is (and how it differs from autocomplete)

Autocomplete suggests; an agent acts. Anthropic puts it simply: in an agent, the model itself decides which steps to take and which tools to use (Schluntz & Zhang, 2024). In programming, those tools mean reading and editing files, running commands in the terminal and executing the tests.

The best-known benchmark for measuring what a coding agent can do is SWE-bench: 2,294 real issues pulled from GitHub across 12 Python projects, which often require changes to several files at once. When it was published, the best model solved only 1.96% of them (Jimenez et al., 2024). Today companies announce far higher scores, but each one measures with its own setup, so those results can't be compared directly with one another.

If you want the general explanation of what an agent is, with examples that go beyond programming, you'll find it in what AI agents are.

Claude Code (Anthropic)

According to its documentation, Claude Code is a tool that reads your project, edits files, runs commands and integrates with the development tools you already use (Anthropic, n.d.-a).

• Where you use it: it started in the terminal, but today it also has a VS Code extension (which works just the same in Cursor), a JetBrains plugin, a desktop app and a web version, plus integrations with GitHub Actions, GitLab and Slack (Anthropic, n.d.-a).
• Customization: a CLAUDE.md file with the project's rules, custom skills, automatic actions before or after each step (hooks), subagents and connections to external tools through MCP (Anthropic, n.d.-a).
• Models: Anthropic's only. As of September 2026 they are Fable 5.1, Opus 5.5, Sonnet 5 and Haiku 4.5, and Anthropic recommends starting with Opus 5.5 for most tasks (Anthropic, n.d.-b).
• Price: the free plan doesn't include it, but every paid plan does: Pro at $20/month, Max at $100 or $200/month depending on usage, and Team from $25 per person per month (Anthropic, n.d.-c, n.d.-d). You can also use it on a pay-as-you-go basis with an API key.

Its strength is how well it lends itself to automation: you can launch it from a script, combine it with other tools and tailor it deeply to each project. Its main limitation is that it only works with Anthropic's models.

Codex (OpenAI)

Codex is OpenAI's coding agent. It runs in the terminal, as an editor extension, as a desktop app and in the cloud (OpenAI, n.d.-a). The terminal version is open source, licensed under Apache 2.0, and runs locally on your computer (OpenAI, n.d.-d).

• Models: OpenAI's only (OpenAI, n.d.-c).
• Price: it's included in every ChatGPT plan, even the free one, with limited usage. Go costs $8/month, Plus $20/month and Pro $100 or $200/month, with five or twenty times as much Codex usage as Plus. Business costs $25 per user per month, and there's also a pay-as-you-go option with an API key (OpenAI, n.d.-b).

Its big advantage is a practical one: if you already pay for ChatGPT, you already have Codex, and you don't need another subscription to try it.

Cursor

Cursor is something different: a full code editor, based on VS Code, with AI built in. Its Agent mode completes complex tasks autonomously, runs commands in the terminal and edits the code (Cursor, n.d.-c). It also offers a terminal version and cloud agents that deliver changes ready for review (Cursor, n.d.-d, n.d.-e).

• Models: this is where it really stands apart. In addition to its own models, it lets you choose among those from Anthropic, OpenAI, Google and other companies (Cursor, n.d.-a).
• Owner: since August 2026, Cursor has been part of SpaceX (Cursor Team, 2026). For now it still offers models from other companies.
• Price: Hobby is free, Pro costs $20/month, Pro+ $60/month and Ultra $200/month. For teams, it's $40 or $120 per user per month. Each plan includes a set amount of usage, which goes considerably further with Cursor's own models than with those from other companies (Cursor, n.d.-b, n.d.-f).

It's the most comfortable option if you like to see changes inside the editor, accept or reject them line by line, and switch models depending on the task.

Quick comparison (September 2026)

Prices change often; these were checked on the official pages on September 27, 2026 (Anthropic, n.d.-c; OpenAI, n.d.-b; Cursor, n.d.-b).

Which one to choose

• If you mostly work in the terminal and want to automate tasks: Claude Code or Codex.
• If you'd rather see and approve every change in the editor: Cursor.
• If you already pay for ChatGPT, start with Codex, since it's already included; if you already pay for Claude, the same goes for Claude Code.
• If you want to try models from several companies without tying yourself to any one of them: Cursor.
• They aren't mutually exclusive: Claude Code installs inside Cursor as an extension (Anthropic, n.d.-a), and plenty of people use both.

In a Stack Overflow survey from April 2026, the most-used coding agents over the previous six months were GitHub Copilot (41%), Claude Code (26%), Codex (22%) and Cursor (22%) (Yepis, 2026). Copilot, which isn't part of this comparison, remains the most widespread.

Behind each tool is a company with its own agent strategy, which I cover in AI agents from OpenAI, Google, Microsoft and Anthropic, compared. And if you're looking for an agent that works without sending your code to the cloud, I explain how in local AI agents.

Do they really make you code faster?

The honest answer is that it isn't clear. The most-cited study was carried out by METR in 2025 with 16 experienced developers working on their own open-source projects, mostly with Cursor. With AI, they took 19% longer. The curious part is that they expected to be 24% faster and, once they were done, were still convinced they had gained 20% in speed (Becker et al., 2025). The authors point out that the result doesn't necessarily apply to all programmers.

In 2026, METR repeated the study with newer tools, including Claude Code and Codex. This time the data suggest that AI does speed up the work, but with a margin of error so wide that it can't be stated with confidence. METR also cautions that the real improvement is probably larger than the measured one, because many participants refused to do the tasks they found most tedious without AI (Becker et al., 2026).

Trust isn't high either. In the 2025 Stack Overflow survey, 84% of developers were using or planning to use AI tools, but only 33% trusted the accuracy of their output. The most common complaint, at 66%, was code that is almost right, but not quite (Stack Overflow, 2025).

My practical takeaway: agents save a lot of time on repetitive tasks and in projects you don't know, but you have to review everything they do. The time you save writing code, you can lose reviewing it.

Frequently asked questions

Which AI coding agent is better, Claude Code, Codex, or Cursor?

None of them wins at everything. Claude Code stands out if you work in the terminal and want to automate; Codex, if you already pay for ChatGPT; and Cursor, if you'd rather review changes inside the editor and choose the model. All three have plans at $20/month or less (Anthropic, n.d.-c; OpenAI, n.d.-b; Cursor, n.d.-b).

Which AI is better for coding, Claude Code or Cursor?

It depends on how you work. Claude Code is a highly customizable terminal agent, while Cursor is a full editor with several models to choose from. And they aren't mutually exclusive: Claude Code installs as an extension inside Cursor (Anthropic, n.d.-a).

Can you make AI agents with Claude Code?

Yes. Anthropic offers the Agent SDK, which gives you the same tools, the same agent loop and the same context management that Claude Code uses, so you can build your own agents in Python or TypeScript (Anthropic, n.d.-e).

Which AI coding agent is better, Codex or Claude Code?

They do very similar things: both read the project, edit files and run commands. The practical difference lies in the models they use, OpenAI's only or Anthropic's only, and in which subscription you already have (OpenAI, n.d.-b; Anthropic, n.d.-c).

Is Codex free?

ChatGPT's free plan includes Codex with limited usage. Paid plans start with Go, at $8/month (OpenAI, n.d.-b).

How much does Cursor cost?

Hobby is free. Pro costs $20/month, Pro+ $60/month and Ultra $200/month; for teams, it's $40 or $120 per user per month (Cursor, n.d.-b).

Keep reading

• →What are AI agents? Explained with examples
• →AI agents from OpenAI, Google, Microsoft and Anthropic, compared
• →Local AI agents: how to run them on your own computer
• →AI agents built a secret message board — then broke into Hugging Face
• →My projects: web apps, automation and AI