How to open a code or text file online
Three steps, a few seconds, no software.
Open your .BAS file
Drop it on the box, choose it from your device, or paste the text straight in.
View it instantly
Your .BAS 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 .BAS file?
Plain text that programs, servers and people write every day.
A BAS file is source code written in some dialect of BASIC, a programming language dating to 1964. Open it in any text editor (Notepad++, VS Code) to read or edit it; to run it you need the matching BASIC compiler or interpreter. One exception: old GW-BASIC or QuickBASIC files saved in binary token format look like gibberish in an editor - they need QB64 or the original interpreter to decode.
Programs that open .BAS files
| Full name | BASIC Source Code File |
|---|---|
| Developer | N/A (BASIC language family — Dartmouth 1964; many dialects) |
| First released | BASIC: 1964 (Dartmouth); .bas widely used since 1980s microcomputers |
| Category | Text & Code |
| MIME type | text/plain |
Related viewers
Every viewer is free to use.
Frequently asked questions
Is my .BAS 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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