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View a 123D file online, free

Open and read .123D files online. View source, logs and text with syntax highlighting, search and line numbers, free.

Drop your .123D file here

Opens your .123D file right here.

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Up to 50 MB · 160+ text and code extensions
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100% free. No limits on use

What you get for a .123D file

We don't have a dedicated viewer for this format, so we identify and inspect it instead — honestly, only what can be read from the file.

01

Drop your .123D file

Choose it or drag it in. It's read right here in your browser.

02

We identify it

We read the magic bytes to tell what the file really is, its MIME type, and whether the name matches the contents.

03

See the details

Any metadata we can extract (dimensions, EXIF/GPS, document author and dates), a hex view, plus readable text and strings found inside.

What is a .123D file?

Plain text that programs, servers and people write every day.

A .123D file is an Autodesk 123D Drawing used for computer-aided design. These files contain three-dimensional models and design data created within the Autodesk software ecosystem. They are primarily opened and edited using Autodesk applications.

Programs that open .123D files

Windows
Autodesk
.123D format details
DeveloperAutodesk

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Frequently asked questions

Is my .123D file uploaded anywhere?

No. The file is read and highlighted for you.

Why do some characters look wrong (é, ł)?

That usually means the file was saved in one encoding and opened in another. We detect UTF-8, UTF-16 and the Windows-1250/1252 code pages automatically and show which one was used.

Can it handle huge log files?

Yes, up to 50 MB. Only the lines on screen are drawn, so scrolling stays smooth. Syntax colours are switched off for files over 1.5 MB to keep things fast.

How do the log level filters work?

We find levels like ERROR, WARN, INFO and DEBUG on each line. Lines without a level, such as stack traces, stay with the entry above them, so filtering to errors keeps the full trace.

Can I edit the file?

This is a viewer. To change code, download it or copy it into your editor. Converting encodings and line endings is planned.

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