Frequently Asked Questions

DigiSim.io is a professional web-based platform for learning, designing, and simulating digital logic circuits. It provides an interactive environment with over 50 components, from basic logic gates to complex CPU architectures, designed for students, educators, and professionals.

No! DigiSim.io runs entirely in your web browser. Simply visit our website and start designing circuits immediately. We recommend using a modern browser like Chrome, Firefox, Safari, or Edge for the best experience.

Yes! We offer a free tier that includes access to core simulator, basic & derived logic gates, I/O components, and essential tools. You can save up to 32 circuits in the cloud and access the first 4 SimCast lessons. For more advanced features and generous cloud storage, consider getting the DigiSim Pro.

Getting started is easy: Navigate to the Playground from the main menu, drag components from the component palette on the left to the workspace, connect components by clicking on output pins and dragging to input pins, use input switches and clocks to control your circuit, and watch output lights and displays show real-time results.

DigiSim.io includes a comprehensive library: Basic Logic Gates (AND, OR, NOT, NAND, NOR, XOR, XNOR, Buffer), Input/Output (Switches, Constants, Output Lights, Seven-Segment Displays), Combinational Logic (Multiplexers, Demultiplexers, Encoders, Decoders), Arithmetic (Half/Full Adders, 4-bit and 8-bit Adders, ALUs, Comparators), Sequential Logic (Flip-Flops, Latches, Registers, Counters), Memory (RAM 256×8, ROM 256×8), CPU Components (Program Counter, Instruction Register, Control Unit), and Advanced (Assembly Program Loader, Oscilloscope, Pixel Screen).

Our platform includes both 4-bit and 8-bit versions of many components. 4-bit components are ideal for learning fundamental concepts and building smaller circuits, while 8-bit components are better for more realistic computer architecture projects and advanced simulations. Note that full CPU components and advanced 8-bit systems are available with the DigiSim Pro.

DigiSim.io uses an advanced event-driven simulation engine that accurately models signal propagation delays and timing behavior. This means you can observe realistic timing relationships, analyze sequential circuits, and understand how real digital systems operate.

The Assembly Program Loader allows you to write assembly code and automatically load it into RAM components. This is perfect for CPU projects where you want to test your processor design with actual programs. It supports a custom assembly language with standard instructions like LDA, STA, ADD, and JMP. This feature is available with the DigiSim Pro, which includes the full CPU component library.

Connecting components is intuitive: Click on an output pin (right side of components), drag to an input pin (left side of components), release to create the connection. Connected pins show their logic state with color coding (high/low/high-impedance).

Make sure you've properly connected all pins and that your input sources (switches, clocks) are set correctly. For sequential circuits, ensure clock signals are connected and that you understand the timing requirements. Use the debugging tools like the oscilloscope to analyze signal timing.

The clock component generates periodic signals essential for sequential circuits. Right-click on the clock to adjust its frequency. Connect the clock output to components that need timing signals, such as flip-flops, registers, and counters.

The Oscilloscope displays voltage waveforms over time and is perfect for analyzing timing relationships, debugging sequential circuits, understanding propagation delays, and verifying clock synchronization. The free tier includes basic timing analysis, while the DigiSim Pro provides an advanced 8-channel oscilloscope for complex analysis.

Building a CPU is one of our most advanced projects and requires the DigiSim Pro for access to the full CPU component library. Start with our demo circuits: Begin with the Program Counter and Clock, add ROM/RAM for instruction and data storage, include the Instruction Register and Control Unit, connect the ALU and processor registers, wire the address and data buses, and use the Assembly Program Loader to test with actual programs.

You can save circuits in two ways: Local Save — use File → Export to download your circuit as a .digi file; Cloud Save — use File → Save (requires account) to store circuits in our cloud with automatic synchronization.

Save limits depend on your license: Free Tier allows 5 circuits in the cloud, and DigiSim Pro provides high-capacity cloud storage for thousands of circuits (subject to Fair Use Policy). Local exports (.digi files) have no limits for all users.

For legitimate human users, the limit is virtually unreachable. Our storage is designed to hold thousands of circuit diagrams — enough for a 4-year degree and beyond. However, to keep the service fast for everyone, we have anti-abuse measures in place to block automated bots or scripts from flooding our servers. As long as you are creating circuits manually, you don't need to worry about limits.

Currently, DigiSim.io uses its own .digi file format optimized for our simulation engine. While we don't directly import from other formats, you can recreate circuits quickly using our intuitive drag-and-drop interface.

SimCast is DigiSim's interactive lesson format — guided tutorials that show step-by-step how to build and understand digital circuits. Each SimCast includes narrated instructions, automatic component placement and connection, educational explanations of circuit principles, and progressive complexity from basic gates to complete systems. The free tier includes access to the first 4 SimCast lessons, while the DigiSim Pro provides access to all 70+ SimCast lessons.

Absolutely! DigiSim.io is designed with education in mind: No software installation required, structured learning progression from basic to advanced concepts, built-in documentation for every component, and demo circuits demonstrating key concepts.

Our platform serves multiple educational levels: High School (basic logic gates and simple circuits), Undergraduate (sequential logic, computer architecture, processor design), Graduate (advanced timing analysis, complex system design), and Professional (prototyping and educational demonstration).

No. This is a one-time purchase. We do not save your credit card for future charges. If you want to continue editing after 12 months, you must manually purchase a new pass. There is no auto-renewal.

You will NEVER lose your projects. After 12 months, your account switches to "Viewer Mode": You CAN login, view your circuits, run simulations, and export your files. You CANNOT create new empty projects or save changes to existing ones. Your data remains safe and accessible forever in Viewer Mode.

Yes. You can purchase a new DigiSim Pro at any time to reactivate your "Edit" and "Save" permissions for another 12 months. Your existing projects will be there waiting for you.

We have a strict "No Data Lock-in" policy. You can download your source files (JSON) at any time. Even if our servers go offline, you possess the raw data of your designs. We guarantee a minimum 30-day notice period with full export access before any shutdown.

Absolutely! The "Viewer Mode" is specifically designed for students. It ensures that even after you graduate or finish the course, you can still show your designs to future employers or professors without paying extra fees.

We're committed to supporting education. Contact our team at education@digisim.io to discuss educational pricing for schools, universities, and qualified educational institutions.

We accept payments through Stripe, which supports major credit cards, debit cards, and various local payment methods. All transactions are secure and encrypted.

All purchases are final and non-refundable, except as required by law. We encourage you to fully explore the free tier before purchasing to ensure DigiSim meets your needs.

DigiSim.io works best on modern browsers: Recommended: Chrome 90+, Firefox 88+, Safari 14+, Edge 90+. Required: JavaScript enabled, minimum 1GB RAM. Optimal: 1920×1080 resolution or higher for the best workspace experience.

For optimal performance: Use a modern browser with hardware acceleration enabled, close unnecessary browser tabs and applications, for large circuits consider breaking them into smaller subcircuits, disable browser extensions that might interfere, and ensure stable internet connection for cloud features.

We value your feedback! You can email us directly at support@digisim.io, use the feedback button in the application, include steps to reproduce any issues, and attach relevant circuit files if applicable.

Yes, we take data security seriously: All data transmission is encrypted using HTTPS, cloud-saved circuits are stored securely with regular backups, we never share your circuits or personal information with third parties, and you maintain full ownership of your circuit designs.

No problem! Use the "Forgot Password" link on the login page to reset your password. You'll receive an email with instructions to create a new password and regain access to your account and saved circuits.