# GrowthBook vs Optimizely Experimentation

> GrowthBook scores 70.1 (BB) on agent readiness against Optimizely Experimentation's 62.6 (B), and leads in 6 of 7 scored categories. Both do analytics experiments. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-08

GrowthBook scores 70.1 (BB) on agent readiness against Optimizely Experimentation's 62.6 (B), and leads in 6 of 7 scored categories. Both do analytics experiments.

- GrowthBook: grade BB, 70.1/100, rank #142 of 722. Markdown https://www.anchorterminal.com/tools/growthbook.md · JSON https://www.anchorterminal.com/api/v1/tools/growthbook.json
- Optimizely Experimentation: grade B, 62.6/100, rank #330 of 722. Markdown https://www.anchorterminal.com/tools/optimizely.md · JSON https://www.anchorterminal.com/api/v1/tools/optimizely.json

## Which one, for what

### GrowthBook (BB)

Good for: Teams that want flags and experiments analysed against their own warehouse, with an open-source core and a self-hosted option.

Ahead on:
- Reliability, 86 against 73
- Agent ergonomics, 76 against 68
- Payments & pricing, 40 against 0
- Maintenance & community, 89 against 78

Also in its favour:
- Agent-ready, a grade of BB or better
- Runs on your own machine
- Free to start without a card
- Open source

Watch for: The API tools take a path and a JSON string and don't validate payloads, so correct calls depend on the bundled skills

### Optimizely Experimentation (B)

Good for: An agent working for an existing Optimizely customer that lists and creates flags, experiments and audiences, reads experiment results and writes SDK integration code.

Also in its favour:
- No incidents deducted, where GrowthBook loses 3 points for them

Watch for: No price is published. The plans page says every plan is individually packaged and leads to a demo request


## Score by category

| Category | Weight | GrowthBook | Optimizely Experimentation | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 86 | 73 | GrowthBook +13 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 76 | 74 | GrowthBook +2 |
| Agent ergonomics | 13% (16.2 this run) | 76 | 68 | GrowthBook +8 |
| Security & auth | 14% (17.5 this run) | 68 | 66 | GrowthBook +2 |
| Payments & pricing | 10% (12.5 this run) | 40 | 0 | GrowthBook +40 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 89 | 78 | GrowthBook +11 |
| Transparency & trust | 7% (8.8 this run) | 74 | 75 | Optimizely Experimentation +1 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **70.1 · BB** | **62.6 · B** | |

## Facts side by side

| Fact | GrowthBook | Optimizely Experimentation |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | GrowthBook, Inc. | Optimizely |
| Hosted endpoint | `https://mcp.growthbook.io/mcp` | `https://exp.mcp.opal.optimizely.com/mcp` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP |
| Auth | OAuth or key | OAuth or key |
| Pricing | Freemium | Paid |
| x402 | no | no |
| Licence | MIT for the core and for the MCP server. Three enterprise directories in the main repository are under GrowthBook's enterprise licence. GrowthBook Cloud is a hosted service under the Customer Agreement | Proprietary hosted service under Optimizely's Online Software Subscription Agreement and its API, SDK and MCP terms. The Feature Experimentation SDKs on GitHub are Apache 2.0 |
| Tools exposed | 4 | 7 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| MCP registry | `io.github.growthbook/growthbook-mcp` | not listed |
| Last release | 2026-10-06 | 2026-09-18 |
| Terms last updated | 2025-06-19 | no date given |
| Privacy policy last updated | 2026-06-08 | no date given |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | yes | yes |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | not found in the text |
| Popularity | 8.5k stars, 1.3M npm/wk, 433k PyPI/wk | 460k npm/wk, 86k PyPI/wk |

## Verdicts

**GrowthBook.** GrowthBook Cloud's MCP server has four tools with read and write annotations, OAuth with dynamic client registration, and a 414-operation OpenAPI spec behind it. The free plan needs no card. The API tools pass paths and JSON bodies through without validation, every key is limited to 60 requests a minute, and audit logs are Enterprise only.

**Optimizely Experimentation.** Optimizely Experimentation suits agents working for an existing customer that manage flags and experiments and read results. The hosted MCP server has seven tools behind OAuth and carries the user's permissions, and the main REST API has a public Swagger spec. No price, free plan or trial is published, and no 429 or idempotency guidance was found.

## Before you call either

### GrowthBook

1. Connect to https://mcp.growthbook.io/mcp and complete OAuth in a browser. Use https://mcp.growthbook.io/mcp/api for the two API tools alone
2. Call `growthbook_list_skills` and `growthbook_read_skill` before writing. The API tools don't validate payloads, so use the paths the skill names
3. Stay under 60 requests a minute per key. On 429 wait for the `RateLimit-Reset` seconds before retrying
4. List calls return 10 items by default. Pass `limit` up to 100 and `offset` to page
5. A 422 is a soft warning. Resubmit with `?ignoreWarnings=true` only after reading the message

### Optimizely Experimentation

1. Connect to https://exp.mcp.opal.optimizely.com/mcp and complete OAuth in a browser. The session is time-limited, so expect to sign in again
2. Call `exp_get_schemas` before `exp_execute_query`, and `exp_get_entity_templates` before `exp_manage_entity_lifecycle`, to learn the fields each entity needs
3. Confirm the project and environment with the user before any create or update. Changes go to live Optimizely data
4. Use the Visual Editor for Web Experimentation variation code. The MCP server does not write custom HTML, CSS or JavaScript
5. Over REST, stay under 2 requests a second on `/flags/v1`, 100 a minute on `/v2` and 20 a minute on the results endpoints

## Questions

### Which is better for AI agents, GrowthBook or Optimizely Experimentation?

GrowthBook scores 70.1 (BB) on agent readiness against Optimizely Experimentation's 62.6 (B), and leads in 6 of 7 scored categories.

### Do GrowthBook and Optimizely Experimentation need an API key?

Both take an API key or an OAuth sign-in.

### Can an agent call GrowthBook and Optimizely Experimentation without installing anything?

Yes. GrowthBook has a hosted endpoint at https://mcp.growthbook.io/mcp and Optimizely Experimentation at https://exp.mcp.opal.optimizely.com/mcp.

### Are GrowthBook and Optimizely Experimentation open source?

GrowthBook is open source (MIT for the core and for the MCP server. Three enterprise directories in the main repository are under GrowthBook's enterprise licence. GrowthBook Cloud is a hosted service under the Customer Agreement). No open-source release is listed for Optimizely Experimentation.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/growthbook-vs-optimizely.json, and with the fewest tokens: https://www.anchorterminal.com/compare/growthbook-vs-optimizely.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "growthbook", "b": "optimizely"}`. From a terminal: `anchor compare growthbook optimizely`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/growthbook.json and https://www.anchorterminal.com/api/v1/tools/optimizely.json

## Other comparisons with GrowthBook or Optimizely Experimentation

- [Amplitude vs GrowthBook](https://www.anchorterminal.com/compare/amplitude-vs-growthbook.md)
- [Amplitude vs Optimizely Experimentation](https://www.anchorterminal.com/compare/amplitude-vs-optimizely.md)
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- [Fullstory vs Optimizely Experimentation](https://www.anchorterminal.com/compare/fullstory-vs-optimizely.md)
- [GrowthBook vs Pendo](https://www.anchorterminal.com/compare/growthbook-vs-pendo.md)
- [Mixpanel vs Optimizely Experimentation](https://www.anchorterminal.com/compare/mixpanel-vs-optimizely.md)
- [Optimizely Experimentation vs Pendo](https://www.anchorterminal.com/compare/optimizely-vs-pendo.md)
- [GrowthBook vs Heap](https://www.anchorterminal.com/compare/growthbook-vs-heap.md)
- [GrowthBook vs LaunchDarkly](https://www.anchorterminal.com/compare/growthbook-vs-launchdarkly.md)
- [GrowthBook vs Mixpanel](https://www.anchorterminal.com/compare/growthbook-vs-mixpanel.md)
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- [GrowthBook vs Statsig](https://www.anchorterminal.com/compare/growthbook-vs-statsig.md)
- [Optimizely Experimentation vs PostHog](https://www.anchorterminal.com/compare/optimizely-vs-posthog.md)
- [Optimizely Experimentation vs Statsig](https://www.anchorterminal.com/compare/optimizely-vs-statsig.md)
- [LaunchDarkly vs Optimizely Experimentation](https://www.anchorterminal.com/compare/launchdarkly-vs-optimizely.md)