What is the EWB file format?
.ewb files are proprietary binary circuit design files produced by Electronics Workbench, a schematic-capture and SPICE simulation application developed from the early 1990s. Each file encodes a complete electronic circuit: component placements (resistors, capacitors, transistors, integrated circuits), wire connections expressed as a netlist, component values and parameters, simulation instrument placements such as oscilloscopes and multimeters, and SPICE simulation settings.
The format exists in two closely related internal generations: EWB40 (version 4.x) and EWB50 (version 5.x - the final standalone release, at version 5.12). When National Instruments acquired the Electronics Workbench Group in 2005 and rebranded the software as NI Multisim, the native format shifted to a new .ms* family - .ms9, .ms10, .ms12, .ms14. NI Multisim 10 and later can still import .ewb files from the 5.x era, though Multisim 12.0 has known compatibility issues with them (documented in NI Knowledge Base article kA00Z000001DdwTSAS).
The format is fully proprietary with no public specification and no documented magic bytes. National Instruments was acquired by Emerson in October 2023; Multisim continues under Emerson's Test & Measurement group. Multisim Live (the browser-based edition) is scheduled for end-of-life on 15 September 2026.
Security & safety
RISK: LOWEWB files contain circuit schematics only - no executable code, macros, or scripts. Safe to open and share.
Format details
in a nutshellPrograms that open EWB files
Windows2 apps
NI Multisim (Emerson)
Paid File → Open → change file type filter to 'Electronics Workbench Files (*.ewb)' → select file. NI Multisim 10 has best EWB5 compatibility.
Electronics Workbench 5.12 (legacy)
Free Legacy installer still circulates for EWB 5.12; installs on Windows XP/7 (compatibility mode on Windows 10/11). Native format - opens all EWB files perfectly.
Multisim Live (online) - EOL September 2026
Freemium Multisim Live supports some Multisim formats online, but EWB legacy format support is unconfirmed. Note: Multisim Live is scheduled for end-of-life September 15, 2026. Technical details
deep spec| Encoding | Binary, little-endian (Windows-native byte order) |
| Container | Proprietary Electronics Workbench binary; no public format specification |
| Typical file size | 10 KB - 5 MB depending on circuit complexity |
| Stored data | Component placements, netlist (wire connections), component values and properties, simulation instrument placements, SPICE settings |
| Internal format versions | EWB40 (v4.x) and EWB50 (v5.x); version 5.12 was the final standalone Electronics Workbench release |
| Compression | None (raw binary layout) |
| Netlist encoding | Wire connections stored as component-to-pin pairings forming a SPICE-compatible netlist; the netlist directly drives circuit simulation |
| Multisim compatibility | NI Multisim 10 and later can open EWB 5.x files; Multisim 12.0 has documented import issues (NI KB article kA00Z000001DdwTSAS) |
| Superseded by | NI Multisim `.ms9` / `.ms10` / `.ms12` / `.ms14` format family, introduced with Multisim 6+ |
| Magic bytes | None publicly documented; file identified only by application context |
| Supported platforms | Windows (95, 98, XP era); NI Multisim extended support through Windows 7 and later |
| Current software owner | Emerson Test & Measurement (completed acquisition of National Instruments, October 2023) |
| Released | Early 1990s (Electronics Workbench v4/v5 era) |
| Latest version | EWB 5.x format (final; superseded by .ms* formats in Multisim 6+) |
EWB conversions
Community Q&A
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