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 weekly across 4 engines, published as open data.

Updated 2026-08-04 · 55 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.

Updated weekly55 samples4 enginesmethodology

Sample: 55 AI answers · Window: Jul 7, 2026Aug 4, 2026 (4-week rolling) · trend vs prior 4 weeks (36 answers)

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

Across 55 sampled AI answers from 4 engines, DocuSeal is recommended most often — appearing in 94.5% of recommendations, followed by OpenSign (90.9%) and Documenso (78.2%).

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

#ProductShareTrendEngines
1
DocuSeal

docuseal.com

94.5%

95% CI 85.198.1%

52 mentions · avg pos 3.6

first pick 50%

GEMINI 100%CHATGPT 100%CLAUDE 71.4%PERPLEXITY 95.2%
Claim
2
OpenSign

opensignlabs.com

90.9%

95% CI 80.496.1%

50 mentions · avg pos 4.6

first pick 4%

GEMINI 100%CHATGPT 100%CLAUDE 42.9%PERPLEXITY 95.2%
Claim
3
Documenso

documenso.com

Best for: AI recommends Documenso most when buyers ask lightweight self-hosted e-signature alternatives to costly commercial signing platforms for small teams (100% of those answers)

78.2%

95% CI 65.687.1%

43 mentions · avg pos 4

first pick 9.3%

GEMINI 75%CHATGPT 100%CLAUDE 71.4%PERPLEXITY 76.2%
Claim
4
Signer

Best for: AI recommends Signer most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (100% of those answers)

67.3%

95% CI 54.178.2%

37 mentions · avg pos 5.9

first pick 27%

GEMINI 90%CHATGPT 71.4%CLAUDE 42.9%PERPLEXITY 52.4%
Claim
5
LibreSign

libresign.coop

Best for: AI recommends LibreSign most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (100% of those answers)

58.2%

95% CI 4570.3%

32 mentions · avg pos 7.5

first pick 0%

GEMINI 80%CHATGPT 85.7%CLAUDE 57.1%PERPLEXITY 28.6%
Claim
6
Docker

docker.com

Best for: AI recommends Docker most when buyers ask best open-source e-signature tool I can self-host for signing contracts internally (87.5% of those answers)

56.4%

95% CI 43.368.6%

31 mentions · avg pos 3.8

first pick 35.5%

GEMINI 70%CHATGPT 100%CLAUDE 28.6%PERPLEXITY 38.1%
Claim
7
DocuSign

docusign.com

Best for: AI recommends DocuSign most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (100% of those answers)

54.5%

95% CI 41.567%

30 mentions · avg pos 5.8

first pick 10%

GEMINI 40%CHATGPT 100%CLAUDE 42.9%PERPLEXITY 57.1%
Claim
8
Nextcloud

nextcloud.com

Best for: AI recommends Nextcloud most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (100% of those answers)

54.5%

95% CI 41.567%

30 mentions · avg pos 8.2

first pick 0%

GEMINI 70%CHATGPT 85.7%CLAUDE 57.1%PERPLEXITY 28.6%
Claim
9
PostgreSQL

postgresql.org

Best for: AI recommends PostgreSQL most when buyers ask best open-source e-signature tool I can self-host for signing contracts internally (50% of those answers)

27.3%

95% CI 17.340.2%

15 mentions · avg pos 10.1

first pick 40%

GEMINI 40%CHATGPT 42.9%PERPLEXITY 19%
Claim
10
MongoDB

mongodb.com

Best for: AI recommends MongoDB most when buyers ask best open-source e-signature tool I can self-host for signing contracts internally (37.5% of those answers)

20%

95% CI 11.632.4%

11 mentions · avg pos 6.2

first pick 0%

GEMINI 25%CHATGPT 14.3%PERPLEXITY 23.8%
Claim
11
OpenSSL

Best for: AI recommends OpenSSL most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (37.5% of those answers)

18.2%

95% CI 10.230.3%

10 mentions · avg pos 3.1

first pick 0%

GEMINI 50%
Claim
12
Supersign

supersign.cc

Best for: AI recommends Supersign most when buyers ask best self-hosted digital signature platform that meets legal eIDAS or ESIGN requirements (50% of those answers)

18.2%

95% CI 10.230.3%

10 mentions · avg pos 4.5

first pick 40%

GEMINI 50%
Claim
13
Kubernetes

kubernetes.io

10.9%

95% CI 5.121.8%

6 mentions · avg pos 18.7

first pick 0%

CHATGPT 57.1%PERPLEXITY 9.5%
Claim
14
OnlyOffice

onlyoffice.com

9.1%

95% CI 3.919.6%

5 mentions · avg pos 3.4

first pick 0%

GEMINI 25%
Claim
15
SignServer

Best for: AI recommends SignServer most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (37.5% of those answers)

9.1%

95% CI 3.919.6%

5 mentions · avg pos 5.4

first pick 0%

GEMINI 20%PERPLEXITY 4.8%
Claim
16
WPsigner

wpsigner.com

Best for: AI recommends WPsigner most when buyers ask best self-hosted digital signature platform that meets legal eIDAS or ESIGN requirements (50% of those answers)

7.3%

95% CI 2.917.3%

4 mentions · avg pos 3

first pick 0%

PERPLEXITY 19%
Claim
17
SourceForge

sourceforge.net

Best for: AI recommends SourceForge most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (50% of those answers)

7.3%

95% CI 2.917.3%

4 mentions

first pick 0%

PERPLEXITY 19%
Claim
18
PandaDoc

pandadoc.com

Best for: AI recommends PandaDoc most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (37.5% of those answers)

5.5%

95% CI 1.914.9%

3 mentions · avg pos 2

first pick 33.3%

GEMINI 5%CLAUDE 14.3%PERPLEXITY 4.8%
Claim
19
Zapier AI

zapier.com

5.5%

95% CI 1.914.9%

3 mentions · avg pos 2

first pick 0%

GEMINI 5%PERPLEXITY 9.5%
Claim
20
Caddy

caddyserver.com

5.5%

95% CI 1.914.9%

3 mentions · avg pos 10.7

first pick 0%

GEMINI 5%PERPLEXITY 9.5%
Claim
21
Adobe Sign

adobe.com

Best for: AI recommends Adobe Sign most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (37.5% of those answers)

5.5%

95% CI 1.914.9%

3 mentions

first pick 0%

CHATGPT 14.3%CLAUDE 14.3%PERPLEXITY 4.8%
Claim
22
Veriffy

3.6%

95% CI 112.3%

2 mentions · avg pos 3.5

first pick 0%

GEMINI 10%
Claim
23
JSignPdf

3.6%

95% CI 112.3%

2 mentions · avg pos 5

first pick 0%

GEMINI 10%
Claim
24
LibreOffice

libreoffice.org

3.6%

95% CI 112.3%

2 mentions · avg pos 5

first pick 0%

GEMINI 10%
Claim
25
React

react.dev

3.6%

95% CI 112.3%

2 mentions · avg pos 5.5

first pick 0%

PERPLEXITY 9.5%
Claim
26
OpenAlternative

openalternative.co

Best for: AI recommends OpenAlternative most when buyers ask open-source e-signature alternatives to expensive hosted document signing services (37.5% of those answers)

3.6%

95% CI 112.3%

2 mentions · avg pos 28.5

first pick 0%

CHATGPT 28.6%
Claim
27
FreeSign

freesign.io

3.6%

95% CI 112.3%

2 mentions · avg pos 38

first pick 0%

CHATGPT 28.6%
Claim
28
AWS

aws.amazon.com

1.8%

95% CI 0.39.6%

1 mentions · avg pos 1

first pick 100%

CLAUDE 14.3%
Claim
29
Azure

1.8%

95% CI 0.39.6%

1 mentions · avg pos 1

first pick 100%

CLAUDE 14.3%
Claim
30
E-Sign

1.8%

95% CI 0.39.6%

1 mentions · avg pos 1

first pick 100%

PERPLEXITY 4.8%
Claim
31
MySQL

mysql.com

1.8%

95% CI 0.39.6%

1 mentions · avg pos 1

first pick 100%

PERPLEXITY 4.8%
Claim
32
SQLite

1.8%

95% CI 0.39.6%

1 mentions · avg pos 1

first pick 100%

PERPLEXITY 4.8%
Claim
33
Sproof Sign

1.8%

95% CI 0.39.6%

1 mentions · avg pos 2

first pick 0%

PERPLEXITY 4.8%
Claim
34
HelloSign

hellosign.com

1.8%

95% CI 0.39.6%

1 mentions · avg pos 3

first pick 0%

GEMINI 5%
Claim
35
Parse Server

1.8%

95% CI 0.39.6%

1 mentions · avg pos 3

first pick 0%

PERPLEXITY 4.8%
Claim
36
Binhex Cloud (Sign)

1.8%

95% CI 0.39.6%

1 mentions · avg pos 5

first pick 0%

GEMINI 5%
Claim
37
SignServer Community

1.8%

95% CI 0.39.6%

1 mentions · avg pos 5

first pick 0%

GEMINI 5%
Claim
38
eIDAS Advanced Electronic Signature Client

1.8%

95% CI 0.39.6%

1 mentions · avg pos 6

first pick 0%

GEMINI 5%
Claim
39
eSignature DSS

1.8%

95% CI 0.39.6%

1 mentions · avg pos 6

first pick 0%

GEMINI 5%
Claim
40
eSign.AI

1.8%

95% CI 0.39.6%

1 mentions · avg pos 20

first pick 0%

CHATGPT 14.3%
Claim
41
Redis

redis.io

1.8%

95% CI 0.39.6%

1 mentions · avg pos 78

first pick 0%

CHATGPT 14.3%
Claim
42
Blueink

blueink.com

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim
43
Docupilot

docupilot.com

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim
44
F6S

f6s.com

Best for: AI recommends F6S most when buyers ask best self-hosted digital signature platform that meets legal eIDAS or ESIGN requirements (37.5% of those answers)

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim
45
GetAccept

getaccept.com

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim
46
Hostinger

hostinger.com

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim
47
Inkless

useinkless.com

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim
48
Open eSignForms

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim
49
Signeasy

signeasy.com

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim
50
Sliplane

sliplane.io

Best for: AI recommends Sliplane most when buyers ask lightweight self-hosted e-signature alternatives to costly commercial signing platforms for small teams (37.5% of those answers)

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

CLAUDE 14.3%
Claim
51
The Digital Project Manager

thedigitalprojectmanager.com

1.8%

95% CI 0.39.6%

1 mentions

first pick 0%

PERPLEXITY 4.8%
Claim

Reading the numbers: Share is a point estimate on 55 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.

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