Open .cir Files Online Free — No Software Needed
Open NGSPICE File Online — Free & Instant
No signup required. Works in your browser.
📁 Drag & drop your file here
or click to browse • Max 100MB
✅ Free • ⚡ Instant • 🔒 Secure • 💻 No install
What Is a .cir File?
NGSPICE (.cir) is a scientific file format. ngspice Circuit File It is commonly used by researchers and academics and created by ngspice.
Step-by-Step: How to Open .cir Files in 2026
Follow these steps to open any .cir file online without installing software:
- Go to OpenAnyFile: Navigate to openanyfile.app
- Upload: Drag and drop your .cir file or click Browse
- Auto-detection: The system identifies the NGSPICE format using signature analysis
- View: Analyze and visualize the file contents in the browser
- Analyze: Use AI-powered analysis to understand the file structure and metadata
- Convert: Optionally convert to TXT
Software That Opens .cir Files
Windows
ngspice can open .cir files natively on Windows. Alternatively, use OpenAnyFile for instant browser access.
macOS
macOS may not natively support .cir files. Use the original application or OpenAnyFile.
Linux
Open-source alternatives or OpenAnyFile provide .cir support on Linux.
Mobile (iPhone & Android)
OpenAnyFile works on all mobile browsers — no app download required.
Common Problems Opening .cir Files
- Your OS doesn't recognize the .cir extension
- The file appears corrupted after downloading
- You don't have ngspice installed
- SPICE dialect differences
OpenAnyFile bypasses all these issues with universal format detection that works in any browser.
Convert NGSPICE to Other Formats
Frequently Asked Questions
What is a .cir file?
A .cir file is a scientific format called NGSPICE. ngspice Circuit File
How do I open a .cir file without installing software?
Upload your .cir file to OpenAnyFile. Our browser-based tool instantly detects and displays it — no downloads needed.
What program creates .cir files?
.cir files are typically created by ngspice.
Can I convert .cir to another format?
Yes. OpenAnyFile converts .cir to TXT.
Is it safe to open .cir files online?
Yes. OpenAnyFile processes files in a secure, isolated environment. Files are automatically deleted and all transfers use HTTPS.
Can I open .cir on my phone?
Yes. OpenAnyFile works on all mobile browsers including iPhone and Android.