How to open a code or text file online
Three steps, a few seconds, no software.
Open your .PYO file
Drop it on the box, choose it from your device, or paste the text straight in.
View it instantly
Your .PYO file opens neatly formatted with line numbers.
Search, copy or download
Search the text, jump to any line, then copy what you need or download a clean copy.
What is a .PYO file?
Plain text that programs, servers and people write every day.
A .pyo file is a legacy Python optimized bytecode cache generated by running Python with the -O or -OO flag. The binary format is identical to a .pyc file. Python 3.5 removed the .pyo extension in 2015 (PEP 488), so if you see one today it comes from Python 2 or Python 3.0 to 3.4. You run it from the command line with a matching Python version, or decompile it back to .py with decompyle3 or uncompyle6.
Programs that open .PYO files
| Full name | Python Optimized Bytecode File (legacy) |
|---|---|
| Developer | Python Software Foundation (CPython) |
| First released | Early CPython (1990s); same as .pyc but with optimizations (assert removal with -O; docstring removal with -OO) |
| Category | Text & Code |
| MIME type | application/x-python-code |
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Frequently asked questions
Is my .PYO 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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