How to open a code or text file online
Three steps, a few seconds, no software.
Open your .INO file
Drop it on the box, choose it from your device, or paste the text straight in.
View it instantly
Your .INO 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 .INO file?
Plain text that programs, servers and people write every day.
An INO file is an Arduino sketch: the C++ source code you write to program an Arduino microcontroller. Open it in the free Arduino IDE (Windows/macOS/Linux) to edit, compile, and upload it to a board. Any text editor opens it for reading. The file must live in a folder with the same name as the sketch; that is an Arduino rule, not a bug.
Programs that open .INO files
| Full name | Arduino Sketch |
|---|---|
| Developer | Arduino (open-source community) |
| First released | 2011 — .ino replaced the older .pde extension in Arduino IDE 1.0 |
| Category | Text & Code |
| MIME type | text/x-arduino |
Related viewers
Every viewer is free to use.
Frequently asked questions
Is my .INO 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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