OpenSign™
Enterprise-Level Document Signing Goes Open-Source
PDF Expert by Readdle
The go-to PDF editor for iPhone, iPad and Mac.
Updated June 2026
| OpenSign™ | PDF Expert by Readdle | |
|---|---|---|
| Rating | 4.0★ | 3.5★ |
| Reviews | 2 | 2 |
| Pros | 0 | 0 |
| FactScore™ | 19.1 | 16.7 |
FactScore™ Comparison
FactScore™ weighs both quality (rating) and popularity (reviews) for a fairer ranking than stars alone.
Pros & Cons
Only in OpenSign™ — Pros
No unique pros listedBoth tools — Pros
—Only in PDF Expert by Readdle — Pros
No unique pros listedOnly in OpenSign™ — Cons
—Both tools — Cons
—Only in PDF Expert by Readdle — Cons
—Details
| OpenSign™ | PDF Expert by Readdle | |
|---|---|---|
| Categories | File storage and sharing apps, PDF Editor, E-signature apps | File storage and sharing apps, PDF Editor, Mobile editing apps |
| Platforms | Web | Web · iOS |
| Added | October 26, 2023 | November 12, 2015 |
| Website | www.opensignlabs.com | pdfexpert.com |
Who Should Pick Which?
Choose OpenSign™ if...
- No unique pros listed
Choose PDF Expert by Readdle if...
- No unique pros listed
With a FactScore™ of 19.1 vs 16.7, OpenSign™ leads in community reception. OpenSign™ uniquely offers No unique pros listed, while PDF Expert by Readdle stands out for No unique pros listed.
What Users Say
OpenSign™
I work as a freelancer, and one of my clients uses this tool for digitally signing all agreements between us. I decided to give it a try as well, and what I like most is how affordable it is while ...
The best digital signing solution, with a simple user interface that I really like. It also offers a self-hosting feature that other alternative tools don't provide.
PDF Expert by Readdle
Fast and convenient PDF experience
Gatekeeping AI features behind subscription paywall vs. those who paid for the standalone app. It would be understandable if only Readdle provided the tokens, but you can't bring your own OpenAI AP...
Related Comparisons
Frequently Asked Questions
Which is better, OpenSign™ or PDF Expert by Readdle?
Based on FactScore™, OpenSign™ leads with a score of 19.1 vs 16.7. OpenSign™ has a higher rating of 4.0★ compared to 3.5★.
What are the pros of OpenSign™ compared to PDF Expert by Readdle?
OpenSign™ uniquely offers: No unique pros listed.
What are the pros of PDF Expert by Readdle compared to OpenSign™?
PDF Expert by Readdle uniquely offers: No unique pros listed.
Is OpenSign™ better rated than PDF Expert by Readdle?
OpenSign™ is rated 4.0★ from 2 reviews. PDF Expert by Readdle is rated 3.5★ from 2 reviews.
What is the FactScore™ of OpenSign™ and PDF Expert by Readdle?
FactScore™ weighs rating and review volume together. OpenSign™ scores 19.1 and PDF Expert by Readdle scores 16.7.
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