CircuitSim

Design and simulate circuits in a browser

CircuitSim combines a schematic editor with an NGspice-based simulation engine and runs in a modern web browser without a desktop installation. Users can place components, draw connections, edit values and see interactive feedback while changing a design. For analysis, the tool supports DC operating point and sweep, AC small-signal analysis, transient simulation and additional SPICE analyses through its netlist editor.

Component library and custom parts

The platform lists a library of more than 5,000 official components, with additional parts added over time and community-contributed options. Users can search for a component and open its detail page, or create their own component in the Custom Component Studio by defining parameters, symbols and interactive behavior. The schematic editor includes wire routing, rotate and mirror controls, multi-select, undo and redo, keyboard shortcuts and SPICE autocomplete.

Charts, measurements and exports

CircuitSim provides live charts and graphing tools for examining voltage, time and frequency response. Cursors help measure values, signals can be overlaid for comparison, and users can view gain and phase across frequency. A design can be exported as a .csim file; schematic images, chart images, SPICE netlists and simulation data can also be exported, including CSV or spreadsheet formats. These outputs support review and further work in other tools.

Classrooms and group licences

The service includes collaboration features for classrooms and teams. Students can share circuits, add notes or comments and view one another's changes. Educators and administrators can manage seats, assign work and organize access from a group dashboard, including private student seats that do not require individual email addresses or passwords. CircuitSim offers a free individual tier and paid plans with larger component libraries, more parts per circuit and group-management tools; educational and corporate bulk pricing is available by enquiry.

Elsewhere Labs and support

CircuitSim is designed and operated by Elsewhere Labs, a small team founded by two friends who build tools intended to simplify complex work. The company describes the simulator as serving education, research, hobby projects and professional prototyping. Support resources include a knowledge base and an idea forum, with hello@circuitsim.com for general enquiries and sales@circuitsim.com for partnerships and group accounts. The provider identifies Elsewhere Labs Ltd as a UK-registered software company; the product itself is browser-based rather than a local engineering consultancy.