AI Index / Open-source e-signature tools

Best Open-source e-signature tools

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

Updated 2026-09-18 · 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 18, 2026

Sample: 28 AI answers · Window: Aug 21, 2026Sep 18, 2026 (4-week rolling) · trend vs prior 4 weeks (97 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 e-signature tools?

Across 28 sampled AI answers from 4 engines, DocuSeal is recommended most often — appearing in 96.4% of recommendations, followed by OpenSign (82.1%) and Documenso (78.6%).

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 e-signature tools and sampled 28 answers between Aug 21, 2026 and Sep 18, 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.

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

docuseal.com

96.4%

95% CI 82.399.4%

27 mentions · avg pos 2

first pick 51.9%

GEMINI 100%CHATGPT 100%CLAUDE 85.7%PERPLEXITY 100%
Claim
2

opensignlabs.com

82.1%

95% CI 64.492.1%

23 mentions · avg pos 4.2

first pick 0%

GEMINI 85.7%CHATGPT 100%CLAUDE 57.1%PERPLEXITY 85.7%
Claim
3

documenso.com

78.6%

95% CI 60.589.8%

22 mentions · avg pos 3.3

first pick 22.7%

GEMINI 71.4%CHATGPT 100%CLAUDE 71.4%PERPLEXITY 71.4%
Claim
4

docker.com

57.1%

95% CI 39.173.5%

16 mentions · avg pos 2.8

first pick 50%

GEMINI 71.4%CHATGPT 85.7%CLAUDE 42.9%PERPLEXITY 28.6%
Claim
Pricing: Pro: $11 a month, $9 a year (free tier available) ↗ source · verified Sep 5, 2026
Features: Docker Scout ↗ source · verified Sep 5, 2026
Platforms: Linux ↗ source · verified Sep 5, 2026
5
Signer

46.4%

95% CI 29.564.2%

13 mentions · avg pos 2.1

first pick 30.8%

GEMINI 100%CLAUDE 57.1%PERPLEXITY 28.6%
Claim
6

libresign.coop

46.4%

95% CI 29.564.2%

13 mentions · avg pos 4.7

first pick 0%

GEMINI 71.4%CLAUDE 71.4%PERPLEXITY 42.9%
Claim
7

docusign.com

42.9%

95% CI 26.560.9%

12 mentions · avg pos 4.8

first pick 8.3%

GEMINI 57.1%CHATGPT 42.9%CLAUDE 28.6%PERPLEXITY 42.9%
Claim
8

nextcloud.com

39.3%

95% CI 23.657.6%

11 mentions · avg pos 5.2

first pick 0%

GEMINI 57.1%CLAUDE 71.4%PERPLEXITY 28.6%
Claim
Features: Forms and surveys ↗ source · verified Sep 5, 2026
Platforms: iOS ↗ source · verified Sep 5, 2026
Integrations: Jira ↗ source · verified Sep 5, 2026
9

postgresql.org

25%

95% CI 12.743.4%

7 mentions · avg pos 3

first pick 28.6%

GEMINI 28.6%CHATGPT 42.9%CLAUDE 14.3%PERPLEXITY 14.3%
Claim
Features: object-relational database system ↗ source · verified Sep 5, 2026
10

supersign.cc

17.9%

95% CI 7.935.6%

5 mentions · avg pos 1.3

first pick 60%

GEMINI 42.9%PERPLEXITY 28.6%
Claim
11

kubernetes.io

14.3%

95% CI 5.731.5%

4 mentions · avg pos 1.3

first pick 75%

CHATGPT 57.1%
Claim
Features: Automated rollouts and rollbacks ↗ source · verified Sep 5, 2026
12
OpenSSL

14.3%

95% CI 5.731.5%

4 mentions · avg pos 8

first pick 0%

GEMINI 42.9%CLAUDE 14.3%
Claim
13

hellosign.com

7.1%

95% CI 222.6%

2 mentions · avg pos 3

first pick 0%

GEMINI 14.3%CLAUDE 14.3%
Claim
14
SignServer

7.1%

95% CI 222.6%

2 mentions · avg pos 4

first pick 0%

GEMINI 14.3%CHATGPT 14.3%
Claim
15

mongodb.com

7.1%

95% CI 222.6%

2 mentions · avg pos 6

first pick 0%

CLAUDE 14.3%PERPLEXITY 14.3%
Claim
Pricing: M2: $9 a month (free tier available) ↗ source · verified Sep 5, 2026
Features: Graph data support ↗ source · verified Sep 5, 2026
Platforms: AWS ↗ source · verified Sep 5, 2026
Integrations: Apache Kafka ↗ source · verified Sep 5, 2026
16

caddyserver.com

7.1%

95% CI 222.6%

2 mentions · avg pos 10

first pick 0%

CLAUDE 14.3%PERPLEXITY 14.3%
Claim
17

nginx.org

7.1%

95% CI 222.6%

2 mentions · avg pos 10

first pick 0%

CLAUDE 14.3%PERPLEXITY 14.3%
Claim
18

make.com

3.6%

95% CI 0.617.7%

1 mentions · avg pos 1

first pick 100%

CHATGPT 14.3%
Claim
19

fedramp.gov

3.6%

95% CI 0.617.7%

1 mentions · avg pos 2

first pick 0%

CLAUDE 14.3%
Claim
20
JSignPdf

3.6%

95% CI 0.617.7%

1 mentions · avg pos 5

first pick 0%

PERPLEXITY 14.3%
Claim
21
Open eSignForms

3.6%

95% CI 0.617.7%

1 mentions · avg pos 5

first pick 0%

PERPLEXITY 14.3%
Claim
22
Sign PDF

3.6%

95% CI 0.617.7%

1 mentions · avg pos 7

first pick 0%

CLAUDE 14.3%
Claim
23
E-Sign

3.6%

95% CI 0.617.7%

1 mentions · avg pos 8

first pick 0%

GEMINI 14.3%
Claim

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 e-signature tools. No account needed.

Compare the leaders

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

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 e-signature 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 e-signature tools

What is the best open-source e-signature tools?

Across 28 sampled AI answers from 4 engines (Aug 21, 2026 to Sep 18, 2026), DocuSeal is recommended most often for open-source e-signature tools, appearing in 96.4% of recommendations, followed by OpenSign (82.1%). This is a measurement of what AI assistants recommend, not an editorial verdict.

What does ChatGPT recommend for open-source e-signature tools?

ChatGPT recommends DocuSeal most often for open-source e-signature tools. It appears as a recommendation in 100% of ChatGPT's sampled answers in this window (Aug 21, 2026 to Sep 18, 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 e-signature tools ranking is based on 28 answers in the current 4-week window (Aug 21, 2026 to Sep 18, 2026). Full methodology is published at https://www.orbator.io/ai-index/methodology.

Compare the top open-source e-signature tools side by side

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

Dockerdocker.comNextcloudnextcloud.comPostgreSQLpostgresql.orgKuberneteskubernetes.ioMongoDBmongodb.com
PricingPro: $11 a month, $9 a year (free tier available) ↗ sourceverified Sep 5, 2026M2: $9 a month (free tier available) ↗ sourceverified Sep 5, 2026
FeaturesDocker Scout ↗ sourceverified Sep 5, 2026Forms and surveys ↗ sourceverified Sep 5, 2026object-relational database system ↗ sourceverified Sep 5, 2026Automated rollouts and rollbacks ↗ sourceverified Sep 5, 2026Graph data support ↗ sourceverified Sep 5, 2026
PlatformsLinux ↗ sourceverified Sep 5, 2026iOS ↗ sourceverified Sep 5, 2026AWS ↗ sourceverified Sep 5, 2026
IntegrationsJira ↗ sourceverified Sep 5, 2026Apache Kafka ↗ sourceverified Sep 5, 2026

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