What is the IRF file format?
.irf is a 2D illustration file format associated with Autodesk Impression. .irf files store layered drawings with Impression's characteristic stylization effects - pencil, ink and watercolour rendering applied to geometry imported from DWG files in AutoCAD. The format is proprietary and binary, with no public specification.
.irf files are rarely seen today as the Impression software program has been discontinued. AutoCAD licence holders could at one time download Impression from Autodesk's product enhancements page free of charge, but Impression is no longer officially available or supported, and it does not run correctly on Windows 10 or 11. AutoCAD can import some .irf content, but full fidelity restoration is not guaranteed.
.irf is also the name of a video format typically used with CCTV surveillance recordings. This unrelated format is supported by software tools developed by Iview. It uses H.264 encoding and can be converted to AVI.
Security & safety
RISK: LOWIRF is a static proprietary CAD illustration format with no known macro or scripting capability. No security concerns beyond the usual risk of opening files from untrusted sources in any application.
Format details
in a nutshell- Impulse Response File (audio) - Some audio software (e.g., convolution reverb plugins) use .irf for impulse response data; unrelated to Autodesk.
- Image Resource File (generic) - A few older tools use .irf as a generic image/resource container; context-dependent.
Programs that open IRF files
Windows2 apps
Autodesk Impression 3 (discontinued)
Free (legacy; no longer officially distr Install Impression 3 on a Windows Vista/7 VM, then File → Open the .irf file. Requires a compatible older DWG library.
AutoCAD (partial)
Paid AutoCAD may import some IRF content via File → Open; full stylization data is not preserved. Technical details
deep spec| Developer | Autodesk, Inc. |
| Encoding | Binary (proprietary, undocumented) |
| Specification | No public documentation; closed proprietary format |
| Color depth | 24-bit RGB (full-color illustration output) |
| Dimensions | Vector-based; resolution-independent |
| Content | 2D illustration layers, stylization effects (pencil, ink, watercolour), DWG-imported geometry |
| Designed workflow | Import DWG from AutoCAD, apply stylizations in Impression, save as .irf |
| Software status | Autodesk Impression discontinued ~2011-2012; does not run on Windows 10/11 |
| Typical file size | 50 KB - 20 MB |
| Platform | Windows only |
| Version history | Impression 1.0 (2007), 2.0, 3.0 (~2010, last release) |
| Interoperability | AutoCAD can import some .irf content; full fidelity restoration not guaranteed |
| Released | 2007 (Autodesk Impression 1.0) |
| Latest version | Autodesk Impression 3.0 (last release, ~2010) |
IRF conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about IRF files.
