Proof (formerly Notarize)
The world's leading identity-assured transaction platform and RON provider.
The API-first, pay-as-you-go e-signature platform for modern developers and high-growth automation.
eSignatures.io represents a paradigm shift in the digital signature market, prioritizing a strictly usage-based architecture over traditional per-seat subscription models. As we move into 2026, the platform maintains its dominance among developers and enterprises looking for a high-degree of programmatic control. Technically, it is built on a robust REST API that facilitates the dynamic generation of contracts from HTML templates or existing PDF overlays. Its most significant market differentiator is its 'Pay-As-You-Go' pricing model, which eliminates the friction of monthly overhead for seasonal or low-volume businesses, while offering aggressive scalability for high-volume automated workflows. The platform is engineered for high completion rates through mobile-first delivery mechanisms, specifically SMS-based signing which bypasses email friction. Its positioning is targeted at technical product teams, legal-tech startups, and logistics firms that require deep integration, complete white-labeling (including custom domains and branding), and real-time status tracking via sophisticated webhook systems. Unlike legacy competitors, eSignatures.io avoids 'feature bloat,' focusing instead on reliability, security, and developer experience.
Direct delivery of signing links via SMS, bypassing email inboxes and leveraging mobile device biometrics.
The world's leading identity-assured transaction platform and RON provider.
The API-first eSignature solution for seamless document workflows and legally binding signatures.
AI-powered document automation to accelerate deal cycles and streamline eSignatures.
The intelligent agreement management platform that accelerates business through AI-driven workflows.
Verified feedback from the global deployment network.
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Complete removal of eSignatures.io branding, supporting custom domains (e.g., sign.yourcompany.com) and custom SMTP.
Developers can send raw HTML content to be rendered into a signed PDF document.
Logic-based routing to determine the order in which multiple parties receive and sign a document.
Advanced field mapping that allows data from CRM systems to automatically populate document fields via API.
Every document includes a detailed log of IP addresses, timestamps, and a unique hash to ensure non-repudiation.
Upload a CSV file to trigger hundreds of personalized signature requests simultaneously.
Manual lease preparation is slow and prone to errors in high-volume property management.
Registry Updated:2/7/2026
Signed PDF is automatically uploaded back to CRM via Webhook.
Ensuring 500+ employees sign an updated handbook without chasing them individually.
Friction during user sign-up when users have to leave the app to check email for documents.