Best JavaScript Libraries for Freelancers

SurveyJS is an embeddable, self-hosted, white-label form builder for teams building custom forms, surveys, questionnaires, and other data collection tools inside web applications. It runs entirely on the client and is fully compatible with all modern JavaScript frameworks, including React, Angular, and Vue. SurveyJS integrates with any backend, giving you full control over data, security, user access, deployment, and business logic. Instead of hardcoding forms, you can empower non-technical users to generate and edit JSON schema-based form configurations through a drag-and-drop form builder. Create dynamic forms with custom conditional logic, validation, multilingual support, PDF export, and analytics. Ideal for SaaS, enterprise software, HR, healthcare, fintech, and other regulated industries, SurveyJS helps teams reduce engineering effort, standardize data collection, maintain full control over data, and deliver unlimited forms that match their brand and feel native to users.

JointJS is a powerful JavaScript diagramming library that helps developers and companies of any size build advanced visual and No-Code applications. It comes in two versions: open-source (JointJS) with limited features and professional (JointJS+), which extends the features of JointJS and offers a wide range of customizable features, ready-to-implement demo applications and white-glove support.