kitio.aiOpenAI Codex vs Tessl
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. OpenAI Codex has the lower starting price: about $8 a month, against $100 for Tessl.
At a glance
Best for
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Cloud coding tasks
- Codex CLI
- IDE extension
- Desktop app
- Automatic PR review
- Skills and plugin registry
- Skill activation analytics
- Before-and-after evals
- Tessl agent
- Spending limits
- Self-hosted option
| Feature | OpenAI Codex | Tessl |
|---|---|---|
| Best for | OpenAI's coding agent in the cloud, CLI, IDE and desktop app | Registry and evals for the skills and context coding agents use |
| Category | Coding | Coding |
| Pricing model | Freemium | Freemium |
| Starting price | $8/mo | $100/mo |
| Free plan | Yes | Yes |
| Made by | OpenAI | Tessl |
| Based in | United States | United Kingdom |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Pricing compared
OpenAI Codex has the lower starting price: about $8 a month, against $100 for Tessl.
Free plan
Cheapest paid plan
Top plan
Free trial
6 plans
Free
Free
- Limited Codex usage
- Via ChatGPT account
Go
$8/mo
- ChatGPT Go plan
- More Codex usage than Free
Plus
$20/mo
- ChatGPT Plus plan
- Codex in CLI, IDE and cloud
Pro
$100/mo
- Starting price; $200 and $500 tiers
- Highest Codex limits
Business
$25/mo
- Per user
- Shared workspace and admin controls
Enterprise
Contact sales
- Enterprise security
- Flexible usage
3 plans
Free
Free
- 1,000 credits per month
- Tessl agent
- Unlimited skills and plugins
- Single workspace
Team
$100/mo
- 5,000 credits per month
- Role management
- Pay-as-you-go beyond credits
Enterprise
Custom
- Bring your own LLM
- Self-hosted deployment
- SLAs and priority support
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
OpenAI Codex
- Included in ChatGPT plans
- Runs many tasks in parallel
- Open-source CLI
- Token-based limits are hard to predict
- Free tier usage is small
Tessl
- Free plan with 1,000 credits a month
- Evals catch skill regressions
- One registry across the org
- Team plan starts at $100 a month
- Frontier models burn credits faster
- Useful mainly for teams already using agents
Which one should you choose?
Choose OpenAI Codex if you want:
- Included in ChatGPT plans
- Runs many tasks in parallel
- Open-source CLI
Watch out: token-based limits are hard to predict.
Choose Tessl if you want:
- Free plan with 1,000 credits a month
- Evals catch skill regressions
- One registry across the org
Watch out: team plan starts at $100 a month.
OpenAI Codex vs Tessl FAQ
What is the difference between OpenAI Codex and Tessl?
OpenAI Codex: OpenAI's coding agent in the cloud, CLI, IDE and desktop app. Tessl: Registry and evals for the skills and context coding agents use. Both are coding tools.
Is OpenAI Codex or Tessl cheaper?
OpenAI Codex has the lower starting price: about $8 a month, against $100 for Tessl.
Do OpenAI Codex and Tessl have free plans?
OpenAI Codex: Yes. Tessl: Yes.
Who makes OpenAI Codex?
OpenAI Codex is made by OpenAI, based in United States.
Who makes Tessl?
Tessl is made by Tessl, based in United Kingdom.
Which should I choose, OpenAI Codex or Tessl?
Choose OpenAI Codex if you value included in chatgpt plans and runs many tasks in parallel. Choose Tessl if you value free plan with 1,000 credits a month and evals catch skill regressions.