OriginLab Origin Project (legacy .opj)
.opjOriginLab Origin (versions before 2018, prior to the .opju switch — the old binary project format)
What it is
The OLD OriginLab project format, used before Origin switched to the ZIP-based .opju container. It is a fully proprietary, undocumented binary layout with no public specification and no available open-source reader we could find or verify against.
Who produces it
Older installations of OriginLab Origin (pre-2018), or newer Origin sessions that were explicitly saved in the legacy .opj format for backward compatibility.
What we read / what we don't read
What we read
Nothing — see below.
What we don't read
- Everything — .opj has never been reverse-engineered or analyzed by this project. There is no partial support; AltaiPlot recognizes the extension and content signature only to give you an honest, immediate rejection message instead of a confusing crash.
What to do instead
- If you still have access to Origin/OriginPro, open the .opj file there and use File → Save As to re-save it as .opju, then import the .opju file into AltaiPlot instead (fully supported, see the .opju page).
- Alternatively, in Origin, select the worksheet(s) you need and export them individually as .csv or .txt, then import those directly.
- If neither option is available, contact us with the file — we track real .opj requests to decide whether investing in this old format is worth it.
Auditability note: this page's capability claims are sourced fromsrc/renderer/src/engine/v7/import/importers/OriginProjectImporter.ts:11 — see the full format list for every extension AltaiPlot recognizes.