AI Index / Open-source feature flag tools

Best Open-source feature flag tools

What AI assistants actually recommend when buyers ask about open-source feature flag tools — measured on a rolling 4-week window across 4 engines, published as open data.

Updated 2026-09-17 · 28 sampled answers · rolling 4-week window · methodology

Rankings are measured from sampled AI answers — never editorial, never paid. Orbator builds AI-visibility tooling; when Orbator itself appears in any category, it is measured by the same rules as everyone else.

Rolling 4-week window28 samples4 enginesmethodologydata studies

Measured by Orbatormethodology owner Henrik Tellewindow ends Sep 17, 2026

Sample: 28 AI answers · Window: Aug 20, 2026Sep 17, 2026 (4-week rolling) · trend vs prior 4 weeks (98 answers)

Samples by engine: GEMINI 7 (last run Sep 6, 2026) · CHATGPT 7 (last run Sep 6, 2026) · CLAUDE 7 (last run Sep 7, 2026) · PERPLEXITY 7 (last run Sep 6, 2026) · GROK 0 (last run Aug 18, 2026 — stalest)

How these numbers are made: sampling design · prompt provenance · what counts as a mention · what we cannot see

On the record: This ranking is frozen as a dated snapshot every day. View this category's history to see what entered and left the ranking and when, or read what the engines actually said on a given day.

What is the best open-source feature flag tools?

Across 28 sampled AI answers from 4 engines, Unleash is recommended most often — appearing in 75% of recommendations, followed by GrowthBook (75%) and Flagsmith (67.9%).

This is a measurement of share of voice across 4 AI engines — not an editorial pick. See the full ranking below.

How this ranking is measured

Orbator asked Gemini, ChatGPT, Claude and Perplexity buyer questions about open-source feature flag tools and sampled 28 answers between Aug 20, 2026 and Sep 17, 2026. Recommendation share counts the answers that recommended or listed a product, so a passing mention or a warning adds nothing to it. A category publishes once it holds at least 20 independently sampled answers in the window. Read the full methodology or download this ranking as CSV.

How to choose Open-source feature flag tools

Buyer prompts in this window split five ways, from self-hosting for gradual rollouts to data sovereignty rules in a banking app. Unleash led the recommendation intent at 100% of 12 runs and the best-in-category intent at 91.7% of 12 runs. GrowthBook and Unleash both led the alternatives intent at 100% of 6 runs. Flagsmith led the problem-solving intent, the one about A/B testing and user targeting, at 66.7% of 6 runs, and tied the comparison intent at 33.3% of 6 runs with Unleash. Published pricing, all last verified 2026-09-05, sits at Pay-As-You-Go $75 a month for Unleash, Start-Up $40 a month for Flagsmith, Pro $40 a month for GrowthBook, and Flipt Pro $200 a month, each with a free tier. Weigh which intent matches the shortlisting question in hand.

Written from this window's measured data · not yet reviewed

recommendedlistedneutral mentionwarned againstRecommendation share counts answers that recommend or list it — neutral mentions and warnings shown for transparency
#ProductShareTrendEngines
1

getunleash.io

75%

95% CI 56.687.3%

21 mentions · avg pos 2.3

first pick 42.9%

GEMINI 85.7%CHATGPT 71.4%CLAUDE 71.4%PERPLEXITY 71.4%
Claim
Pricing: Pay-As-You-Go: $75 a month (free tier available) ↗ source · verified Sep 5, 2026
Features: Feature flags ↗ source · verified Sep 5, 2026
Platforms: Docker ↗ source · verified Sep 5, 2026
Integrations: AWS Kiro ↗ source · verified Sep 5, 2026
2

growthbook.io

75%

95% CI 56.687.3%

21 mentions · avg pos 4.5

first pick 9.5%

GEMINI 85.7%CHATGPT 71.4%CLAUDE 71.4%PERPLEXITY 71.4%
Claim
Pricing: Pro: $40 a month (free tier available) ↗ source · verified Sep 5, 2026
Features: Sequential testing ↗ source · verified Sep 5, 2026
Platforms: Web ↗ source · verified Sep 5, 2026
Integrations: Slack ↗ source · verified Sep 5, 2026
3

flagsmith.com

67.9%

95% CI 49.382.1%

19 mentions · avg pos 2.5

first pick 26.3%

GEMINI 85.7%CHATGPT 71.4%CLAUDE 42.9%PERPLEXITY 71.4%
Claim
Pricing: Start-Up: $40 a month (free tier available) ↗ source · verified Sep 5, 2026
Features: Feature Flags & Remote Config ↗ source · verified Sep 5, 2026
Platforms: Web ↗ source · verified Sep 5, 2026
Integrations: Slack ↗ source · verified Sep 5, 2026
4

flipt.io

42.9%

95% CI 26.560.9%

12 mentions · avg pos 3.6

first pick 8.3%

GEMINI 57.1%CHATGPT 42.9%CLAUDE 28.6%PERPLEXITY 42.9%
Claim
Pricing: Flipt Pro: $200 a month (free tier available) ↗ source · verified Sep 5, 2026
Features: Git-native workflows ↗ source · verified Sep 5, 2026
Platforms: REST APIs ↗ source · verified Sep 5, 2026
Integrations: GitHub ↗ source · verified Sep 5, 2026
5

gofeatureflag.io

39.3%

95% CI 23.657.6%

11 mentions · avg pos 6.6

first pick 9.1%

GEMINI 71.4%CHATGPT 28.6%CLAUDE 14.3%PERPLEXITY 42.9%
Claim
6

kubernetes.io

35.7%

95% CI 20.754.2%

10 mentions · avg pos 3

first pick 40%

GEMINI 71.4%CHATGPT 42.9%PERPLEXITY 28.6%
Claim
Features: Automated rollouts and rollbacks ↗ source · verified Sep 5, 2026
7

openfeature.dev

28.6%

95% CI 15.347.1%

8 mentions · avg pos 5.7

first pick 12.5%

GEMINI 71.4%CHATGPT 28.6%CLAUDE 14.3%
Claim
Features: enable, disable or change the behavior of certain features or code paths ↗ source · verified Sep 5, 2026
8

postgresql.org

21.4%

95% CI 10.239.5%

6 mentions · avg pos 5.3

first pick 50%

GEMINI 42.9%CLAUDE 42.9%
Claim
Features: reliability ↗ source · verified Sep 5, 2026
9

posthog.com

21.4%

95% CI 10.239.5%

6 mentions · avg pos 8.3

first pick 0%

GEMINI 57.1%CHATGPT 14.3%CLAUDE 14.3%
Claim
Pricing: Free ↗ source · verified Sep 5, 2026
Features: Product Analytics ↗ source · verified Sep 5, 2026
Platforms: Web ↗ source · verified Sep 5, 2026
Integrations: HubSpot ↗ source · verified Sep 5, 2026
10

featbit.co

14.3%

95% CI 5.731.5%

4 mentions · avg pos 4.5

first pick 0%

GEMINI 42.9%PERPLEXITY 14.3%
Claim
Pricing: Advanced RBAC: $600 a year (free tier available) ↗ source · verified Sep 5, 2026
Features: Feature Toggle ↗ source · verified Sep 5, 2026
Platforms: Kubernetes ↗ source · verified Sep 5, 2026
Integrations: OAuth 2.0 ↗ source · verified Sep 5, 2026
11

docker.com

10.7%

95% CI 3.727.2%

3 mentions · avg pos 2

first pick 0%

GEMINI 14.3%CHATGPT 14.3%PERPLEXITY 14.3%
Claim
Pricing: Pro: $11 a month, $9 a year (free tier available) ↗ source · verified Sep 5, 2026
Features: Testcontainers Cloud ↗ source · verified Sep 5, 2026
Platforms: Windows ↗ source · verified Sep 5, 2026
12

launchdarkly.com

10.7%

95% CI 3.727.2%

3 mentions · avg pos 5

first pick 0%

CHATGPT 28.6%PERPLEXITY 14.3%
Claim
Pricing: Foundation: $10 a month (free tier available) ↗ source · verified Sep 5, 2026
Features: Feature flags ↗ source · verified Sep 5, 2026
Platforms: API ↗ source · verified Sep 5, 2026
Integrations: Slack ↗ source · verified Sep 5, 2026
13

redis.io

10.7%

95% CI 3.727.2%

3 mentions · avg pos 9

first pick 0%

GEMINI 28.6%PERPLEXITY 14.3%
Claim
14

mongodb.com

10.7%

95% CI 3.727.2%

3 mentions · avg pos 10

first pick 0%

CLAUDE 28.6%PERPLEXITY 14.3%
Claim
Pricing: M2: $9 a month (free tier available) ↗ source · verified Sep 5, 2026
Features: Stream Processing ↗ source · verified Sep 5, 2026
Platforms: AWS ↗ source · verified Sep 5, 2026
Integrations: Apache Kafka ↗ source · verified Sep 5, 2026
15

servicenow.com

7.1%

95% CI 222.6%

2 mentions · avg pos 2

first pick 50%

CLAUDE 28.6%
Claim
16

react.dev

7.1%

95% CI 222.6%

2 mentions · avg pos 4

first pick 50%

GEMINI 28.6%
Claim
Features: Asynchronous components ↗ source · verified Sep 5, 2026
Platforms: iOS ↗ source · verified Sep 5, 2026
Integrations: Expo ↗ source · verified Sep 5, 2026
17

aws.amazon.com

7.1%

95% CI 222.6%

2 mentions · avg pos 4.5

first pick 50%

GEMINI 28.6%
Claim
Features: over 240 comprehensive services ↗ source · verified Sep 5, 2026
18

azure.microsoft.com

7.1%

95% CI 222.6%

2 mentions · avg pos 4.5

first pick 50%

GEMINI 28.6%
Claim
19

clickhouse.com

7.1%

95% CI 222.6%

2 mentions · avg pos 6

first pick 0%

GEMINI 28.6%
Claim
20

split.io

7.1%

95% CI 222.6%

2 mentions · avg pos 7.5

first pick 0%

CHATGPT 14.3%PERPLEXITY 14.3%
Claim
21

snowflake.com

7.1%

95% CI 222.6%

2 mentions · avg pos 11.5

first pick 0%

GEMINI 28.6%
Claim
Features: Snowpark ↗ source · verified Sep 5, 2026
Integrations: Coalesce ↗ source · verified Sep 5, 2026
22

angular.io

3.6%

95% CI 0.617.7%

1 mentions · avg pos 1

first pick 100%

GEMINI 14.3%
Claim
23

configcat.com

3.6%

95% CI 0.617.7%

1 mentions · avg pos 3

first pick 0%

PERPLEXITY 14.3%
Claim
24

okta.com

3.6%

95% CI 0.617.7%

1 mentions · avg pos 6

first pick 0%

GEMINI 14.3%
Claim
Pricing: Starter: $6 a month ↗ source · verified Sep 5, 2026
Features: Workflows ↗ source · verified Sep 5, 2026
Platforms: Okta ↗ source · verified Sep 5, 2026
Integrations: LDAP ↗ source · verified Sep 5, 2026
25
flagd

3.6%

95% CI 0.617.7%

1 mentions · avg pos 6

first pick 0%

CHATGPT 14.3%
Claim
26
FF4J

3.6%

95% CI 0.617.7%

1 mentions · avg pos 7

first pick 0%

GEMINI 14.3%
Claim
27

ff4j.org

3.6%

95% CI 0.617.7%

1 mentions · avg pos 7

first pick 0%

GEMINI 14.3%
Claim
28

flippercloud.io

3.6%

95% CI 0.617.7%

1 mentions · avg pos 8

first pick 0%

GEMINI 14.3%
Claim
Pricing: Cloud Bronze: $49 a month, $499 a year (free tier available) ↗ source · verified Sep 5, 2026
Features: Toggle by Group ↗ source · verified Sep 5, 2026
Platforms: API ↗ source · verified Sep 5, 2026
Integrations: Mongo ↗ source · verified Sep 5, 2026

Reading the numbers: Share is a point estimate on 28 sampled answers, so each row also shows its 95% CI — the Wilson score interval around that share. When two products' intervals overlap, the gap between them isn't statistically meaningful at this sample size. First pick is the share of a product's recommending answers where it was named first, which separates “always mentioned” from “usually the top recommendation”. Full methodology.

Independence: Orbator customers are badged for disclosure. Customer status does not affect prompts, sampling, extraction, or ranking — see the methodology. Your product on this list? Claim it to see the prompts behind your rank and track it weekly.

Watch this category

These rankings move. Get one email a week on who AI recommends in Open-source feature flag tools. No account needed.

Compare the leaders

Head-to-head pages for products ranked in Open-source feature flag tools. Each one sets out sourced facts side by side, plus which product AI assistants recommend more, engine by engine.

The top five Open-source feature flag tools, one by one

Unleash was recommended in 81% of 42 sampled answers in the 4-week window to 2026-09-05, the highest share in the category. Its mention breakdown shows 20 runs recommended against 14 listed, with 6 context and 1 warned against. Engine spread runs from 100% of Claude's 7 answers and 100% of Grok's 7 answers down to 57.1% of Perplexity's 7 answers. Pricing is Pay-As-You-Go $75 a month with a free tier, last verified 2026-09-05.

Flagsmith was recommended in 73.8% of 42 sampled answers in the same window, with 20 runs recommended and 11 listed, plus 7 context and 1 warned against. It reached 100% of Grok's 7 answers at the high end and 42.9% of Claude's 7 answers at the low end. Start-Up pricing is $40 a month with a free tier, last verified 2026-09-05.

GrowthBook was recommended in 59.5% of 42 sampled answers, with 14 runs recommended and 11 listed. Claude and Perplexity both sat at 71.4% of their 7 answers; ChatGPT sat lowest at 50% of its 14 answers. Pro pricing is $40 a month with a free tier, last verified 2026-09-05.

Flipt was recommended in 52.4% of 42 sampled answers, split 11 recommended and 11 listed. Grok was highest at 85.7% of 7 answers, ChatGPT lowest at 35.7% of 14 answers. Flipt Pro is $200 a month with a free tier, last verified 2026-09-05.

GO Feature Flag was recommended in 45.2% of 42 sampled answers, with 10 runs recommended and 9 listed. Gemini and Grok both reached 71.4% of their 7 answers, while Claude gave it 14.3% of 7 answers.

Written from this window's measured data · not yet reviewed

Where the engines disagree

Four of the five engines recommended the same product most among the top five. Unleash led for Claude across 7 answers, for Gemini across 7 answers, for Grok across 7 answers, and for ChatGPT across 14 answers. Perplexity was the exception, leading with Flagsmith across its 7 answers.

Flagsmith also carried the widest gap between engines. It was recommended in 42.9% of Claude's 7 answers and 100% of Grok's 7 answers, a spread of 57.1 points. A shortlist built on one engine's output would look different depending on which engine produced it, and for Flagsmith the difference is the largest measured in this category.

Written from this window's measured data · not yet reviewed

What moved this window

This is the first measured window on record for open-source feature flag tools. It runs from 2026-08-08 to 2026-09-05, 28 days, and covers 42 sampled answers across 5 engines. There is no prior window to compare against, so no entries, exits or share changes can be reported yet.

Unleash leads the window at 81% of 42 sampled answers, with Flagsmith at 73.8% and GrowthBook at 59.5% of the same 42. Flipt sits at 52.4% and GO Feature Flag at 45.2%. Unleash was also the first product recommended in 41.2% of the answers that recommended it, the highest first-recommendation rate among the top five. The next window will show whether these positions hold.

Written from this window's measured data · not yet reviewed

What the engines actually said

Every number on this page is measured from sampled answers, and those answers are kept. The archive holds dated excerpts of what each engine answered, never full answers. Read the answer archive for open-source feature flag tools to see the excerpts by date and engine, or view the ranking history to see what entered and left this ranking and when.

Questions buyers ask about Open-source feature flag tools

What is the best open-source feature flag tools?

Across 28 sampled AI answers from 4 engines (Aug 20, 2026 to Sep 17, 2026), Unleash is recommended most often for open-source feature flag tools, appearing in 75% of recommendations, followed by GrowthBook (75%). This is a measurement of what AI assistants recommend, not an editorial verdict.

What does ChatGPT recommend for open-source feature flag tools?

ChatGPT recommends Unleash most often for open-source feature flag tools. It appears as a recommendation in 71.4% of ChatGPT's sampled answers in this window (Aug 20, 2026 to Sep 17, 2026). Other engines answer differently. The per-engine breakdown in the ranking shows each one.

How is this measured?

Orbator samples AI answers to buyer questions across 4 engines and counts how often each product is recommended. No product pays for placement. The open-source feature flag tools ranking is based on 28 answers in the current 4-week window (Aug 20, 2026 to Sep 17, 2026). Full methodology is published at https://www.orbator.io/ai-index/methodology.

Compare the top open-source feature flag tools side by side

Verified facts for the most-recommended products — each sourced and dated. No editorial scoring, just the data side by side.

Unleashgetunleash.ioGrowthBookgrowthbook.ioFlagsmithflagsmith.comFliptflipt.ioKuberneteskubernetes.io
PricingPay-As-You-Go: $75 a month (free tier available) ↗ sourceverified Sep 5, 2026Pro: $40 a month (free tier available) ↗ sourceverified Sep 5, 2026Start-Up: $40 a month (free tier available) ↗ sourceverified Sep 5, 2026Flipt Pro: $200 a month (free tier available) ↗ sourceverified Sep 5, 2026
FeaturesFeature flags ↗ sourceverified Sep 5, 2026Sequential testing ↗ sourceverified Sep 5, 2026Feature Flags & Remote Config ↗ sourceverified Sep 5, 2026Git-native workflows ↗ sourceverified Sep 5, 2026Automated rollouts and rollbacks ↗ sourceverified Sep 5, 2026
PlatformsDocker ↗ sourceverified Sep 5, 2026Web ↗ sourceverified Sep 5, 2026Web ↗ sourceverified Sep 5, 2026REST APIs ↗ sourceverified Sep 5, 2026
IntegrationsAWS Kiro ↗ sourceverified Sep 5, 2026Slack ↗ sourceverified Sep 5, 2026Slack ↗ sourceverified Sep 5, 2026GitHub ↗ sourceverified Sep 5, 2026

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