Amp vs OpenAI Codex

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors.

The short answer

Cheaper paid plan: OpenAI Codex — $8/mo vs $20/mo for Amp
Free plan: Both have one
Public API: Both have one
Best fit: Amp: Developers who already pay for ChatGPT or Claude and want another agent harness at no extra cost · OpenAI Codex: ChatGPT subscribers who want a coding agent included in their plan
Platforms: Amp: Web, macOS, Windows, Linux, iOS · OpenAI Codex: Web, macOS, Windows, Linux, iOS, VS Code extension

From our own records as of each tool's last check. Anything we have not confirmed is left out rather than guessed. How we verify

AmpCoding agent that runs in your terminal, a Mac app or Amp's cloud machines, on your own model subscriptions or keys

OpenAI CodexOpenAI's coding agent for the terminal, IDE, desktop and cloud sandboxes, included with ChatGPT plans or billed by API tokens.

Side by side

Fact	Amp	OpenAI Codex
Category	AI Coding Assistants	AI Coding Assistants
Pricing model	Freemium	Freemium
Starts at	$20/mo	$8/mo
Public API	Yes	Yes
Trust score	96 / 100	96 / 100
Platforms	Web, macOS, Windows, Linux, iOS, API	Web, macOS, Windows, Linux, iOS, VS Code extension, API
Company	Amp Frontier Corporation	OpenAI
Launched	2025	2025
Last verified	Oct 15, 2026	Oct 2, 2026

What our research says

Amp

Amp is now its own company and has turned from a pay-per-token agent into a free agent harness plus paid cloud machines: bring a ChatGPT or Claude subscription or your own keys and the agent itself costs nothing, while $20 or $200 a month buys included usage and orb time. It suits developers who want agents running in parallel on remote machines and can live with a fast-moving beta; teams that want a stable editor plugin and fixed terms should look elsewhere.

Pros

Hobby tier is free with your own subscriptions, keys and runners, with no Amp token fees
Pay-as-you-go model usage at provider API prices with no markup for individuals and non-enterprise workspaces
Teams tier adds thread sharing, multiplayer and SAML/OIDC SSO at no extra charge
Runs from a CLI on macOS, Linux and Windows via WSL, plus Mac and iOS apps and cloud orbs

Cons

Mac and iOS apps are betas that require macOS or iOS 26
Pricing changed three times in 2026, so plans read today may not hold
Orbs are billed by the minute and by size, so larger machines burn the allowance faster
Prepaid credits expire twelve months after purchase

OpenAI Codex

Codex is the obvious pick if you already pay for ChatGPT and want an agent that can work in your terminal or off in a cloud sandbox without a second subscription. It is less compelling if you want a polished editor-native experience or need predictable monthly spend at heavy usage.

Pros

The command-line agent is open source under Apache-2.0
Free and Go tiers let you try it before paying for a bigger plan
Same agent is reachable from terminal, IDE extension, desktop app and cloud tasks
Can sign in with a ChatGPT plan or an API key, whichever billing suits you

Cons

Usage limits on subscription plans vary by model, task and local versus cloud runs, so capacity is hard to predict
Top-tier usage requires the higher Pro plans, which start at $100/month
Surfaces and plan names change often, so docs and pricing pages move around

Which one fits

Choose Amp if you need

Developers who already pay for ChatGPT or Claude and want another agent harness at no extra cost
Running several agents in parallel on cloud machines that keep working with the laptop closed
Small teams that want shared threads, SSO and pooled credits without per-seat fees

Choose OpenAI Codex if you need

ChatGPT subscribers who want a coding agent included in their plan
Developers delegating well-scoped tasks and reviewing the resulting diffs
Teams that want automated pull-request review in GitHub