JWW / DWG / DXF / SXF / DGN / DWF / MI — free CAD viewer & converter
Open CAD drawings in your browser. No CAD required.
View JWW, JWC, DWG, DXF, SXF (SFC/P21), DGN, DWF, and MI drawings right in your browser, convert them to DXF, PDF, SVG, or PNG — and see exactly what was converted and what was lost, every time.
- No signup
- No installation
- Unlimited conversions
- Loss report included
- 01Drop your drawing file
- 02Pick a format & convert
- 03Preview & download
Popular
Popular conversions
The most common conversions — each page converts right on the spot.
Viewer
Just need to open a file?
Check the contents of a drawing in your browser — no CAD installation.
Formats
Supported formats
| Format | Read | Write | Notes |
|---|---|---|---|
| Jw_cad (JWW) | — | ||
| Jw_cad DOS版 (JWC) | — | Beta. Reads DOS-era Jw_cad JWC drawings (lines, circles, arcs, ellipses, text, points); other JWC layouts and JWK/JWS files unsupported | |
| AutoCAD DWG | — | ||
| DXF | AC1009 / AC1024 | Output: R12 (AC1009) / R2010 (AC1024) | |
| SXF (SFC) | — | SXF export planned (Japanese e-delivery) | |
| SXF (P21) | — | P21 input support expanding (SFC first) | |
| MicroStation DGN | — | V7 2D and V8. Multi-model V8 files convert the first model; 3D models are flattened; V7 3D unsupported | |
| Autodesk DWF/DWFx | — | Beta. 2D sheets only — multi-sheet files are merged; W2D before 0.55 unsupported | |
| ME10 / Creo Elements/Direct Drafting MI | — | Beta. Reads text MI and gzip-compressed BI; other BI compression variants unsupported | |
| — | |||
| SVG | — | ||
| PNG | — |
Why zumen-gate
What makes it different
No signup, no limits
No account needed, and no daily caps — convert and download as much as you like.
Loss report
Every conversion discloses what was dropped, approximated, or substituted — entity by entity. No black-box conversions.
Honest format coverage
What we can and can't convert is published openly, with unsupported formats shown as a roadmap.
Comparison
How it compares
Your options when you receive a drawing you can't open:
| zumen-gate | Typical free online converters | Buying CAD software | |
|---|---|---|---|
| Price | Free | Free with restrictions | License or subscription |
| Account | Not required | Often required | Required |
| Usage limits | Unlimited | A few conversions per day | None |
| Installation | None (browser only) | None | Required |
| Quality disclosure | Entity-level loss report | Result only (no details) | Manual inspection |
| JWW / SXF / DGN / DWF / MI support | Yes — built for Japanese formats | Rarely supports JWW/SXF | Depends on the software |
All pairs
All conversion pairs (structural)
These pairs are deterministic, structural conversions. Each page converts right on the spot (β marks newly supported formats).
FAQ
Frequently asked questions
Is it really free? Why is it unlimited?
Yes — viewing and converting are free with no limits on conversions or downloads. On the free tier, uploaded drawings are used to improve the service and train our AI models; that is what funds the free, unlimited service. A paid Pro plan with no training use and immediate deletion is also available.
Do I need an account or any installation?
No. Just drop a file in your browser — viewing, converting, and downloading all happen right there. Latest versions of Chrome, Edge, Safari, and Firefox are supported.
What is a JWW file and how do I open it?
JWW is the native format of Jw_cad, a free CAD application widely used in Japan's architecture industry. Most CAD software outside Japan cannot open it. zumen-gate displays JWW files directly in your browser and converts them to DXF, PDF, SVG, or PNG.
How do I open a JWW file in AutoCAD?
Use the JWW to DXF conversion with the R2010 (AC1024) output version, then open the resulting DXF in AutoCAD. For older CAD software, choose R12 (AC1009) instead.
What are SFC and P21 (SXF) files?
SXF is the Japanese national standard for exchanging public-works CAD drawings; SFC is the lightweight file type and P21 the formal ISO 10303-based one. They are rarely supported outside Japan — zumen-gate opens both in the browser and converts them to DXF or PDF.
Is it safe to upload confidential drawings?
The free tier uses uploads for AI development (training), so please avoid uploading confidential drawings. Transfers and storage are encrypted, and drawings are never sold or shared with third parties. A no-training Pro plan with immediate deletion is available, and an on-premises edition for organizations runs entirely in your own environment.
How do I know the conversion didn't break my drawing?
Every conversion produces a loss report showing, entity by entity, what was converted as-is and what was approximated or dropped — alongside a full preview. You can verify quality before you rely on the output.