About this Salesforce Certified JavaScript Developer I study guide
This page is your Salesforce Certified JavaScript Developer I study guide. The certification validates skills that employers look for in Salesforce roles—whether you're an administrator, consultant, developer, or architect. It is designed for developers and technical implementers who want to prove their knowledge with an industry-recognized credential.
Here you'll find section-wise exam weightage so you know exactly which topics carry the most questions, exam tips and prerequisites, a focused study plan, and sample practice questions with detailed explanations. All content on this page is original and unique—written specifically for this certification to help with both your preparation and search engine indexing. Use this page to align your study with the official outline and to gauge when you're ready to sit the exam. Many candidates use section weightage to prioritize high-value topics and practice questions to build exam-day confidence.
Passing this certification can support career progression, higher earning potential, and recognition in the Salesforce ecosystem. Salesforce exams are updated periodically, so we keep our materials aligned with current objectives.
Last reviewed: January 2025. Salesforce exam outlines may change; always check the official exam guide on Trailhead before booking.
Release compatible: Winter '26 — Study materials and objectives are aligned with the Winter '26 release (compared to Summer '25).
What's new in Winter '26:
- Agentforce and AI: New Agentforce for Service (IT Service), Agentic Commerce, and Agentforce Grid for low-code AI workflows—expect more AI-related objectives on Admin and Consultant exams.
- Data Cloud: Clean Rooms for privacy-safe data collaboration and zero-copy analytics; Data Cloud objectives may include new collaboration and governance topics.
- Automation & Platform: Enhanced automation capabilities and platform updates; Flow, Process Builder, and integration topics remain core—check the official outline for weightage changes.
- Tableau & Analytics: Tableau Next Concierge in Slack and conversational analytics; Tableau certs may reference new Slack and natural-language features.
- Security & Access: Continued focus on identity, access management, and secure data handling; relevant for Administrator and Architect tracks.
Salesforce Certified JavaScript Developer I Study Guide
Certified JavaScript Developers have experience developing front-end and/or back-end JavaScript applications for the web stack, and work with JavaScript related technologies like Lightning Web Components.
Exam Weightage by Section
Exam Topics
Exam Tips
- 1LWC and Aura are 30%—know component lifecycle, decorators, and events.
- 2JavaScript fundamentals: ES6+, async, DOM, and debugging.
- 3Understand when to use LWC vs Aura and migration considerations.
- 4Testing: Jest for LWC, and debugging in browser and VS Code.
Prerequisites
- •JavaScript experience
- •Platform Developer I recommended
Focus Areas
- •JavaScript Fundamentals
- •LWC and Aura
- •Debugging and Testing
- •Performance
Study Strategy
Build at least two LWCs (one with Apex). Practice debugging and unit testing. Memorize key decorators and lifecycle hooks.
Sample Practice Questions
Test your knowledge with these sample questions.
Which JavaScript feature is used to handle asynchronous operations without blocking the main thread?
What is the primary use of Lightning Web Components (LWC) in the Salesforce ecosystem?
Which keyword creates a block-scoped variable in JavaScript?
What does the shadow DOM provide in web components?
Which LWC decorator makes a property available to the component's template?
Want More Practice Questions?
Get access to our complete question bank with detailed explanations.
Contact Us for Full AccessFrequently Asked Questions
- What is covered on the Salesforce Certified JavaScript Developer I exam?
- This page shows the section-wise exam weightage so you know exactly which topics carry the most weight. Use the exam topics and practice questions above to align your study with the official outline.
- Do I need Platform Developer I before JavaScript Developer I?
- While not required, Platform Developer I is highly recommended. JavaScript Developer I focuses specifically on JavaScript, LWC, and Aura, so having PD1 knowledge helps, but you can take it independently if you have strong JavaScript skills.
- What JavaScript concepts are most important for JavaScript Developer I?
- Focus on ES6+ features (arrow functions, promises, async/await), DOM manipulation, JavaScript debugging, LWC lifecycle hooks and decorators, and testing with Jest. The exam is heavily JavaScript-focused.
- How do I prepare for the Salesforce Certified JavaScript Developer I certification?
- Use the exam tips, prerequisites, and study strategy on this page. Focus first on the highest-weighted sections, then take the sample practice questions. Schedule the exam when you consistently score well on practice tests.
- Where can I find the official exam outline for Salesforce Certified JavaScript Developer I?
- Salesforce publishes exam guides and outlines on Trailhead (trailhead.salesforce.com). This page's section weightage and topics are aligned with those outlines to help you prepare.