How to open a code or text file online
Three steps, a few seconds, no software.
Open your .LETTER file
Drop it on the box, choose it from your device, or paste the text straight in.
View it instantly
Your .LETTER 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 .LETTER file?
Plain text that programs, servers and people write every day.
A .LETTER file is an undeliverable mail file that contains text-based information regarding failed email transmissions. These miscellaneous files are typically generated and accessed by the Sendmail program.
Programs that open .LETTER files
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Frequently asked questions
Is my .LETTER 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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