ANSI terminal emulation and conversion to ANSI, HTML, and plain text

erbsland-ansi-convert is a Python 3.10+ library that simulates an ANSI terminal and converts the resulting terminal history into:

• Plain text
• Compact ANSI text
• Compact HTML with CSS classes

It is designed to process terminal output from tools that emit ANSI escape sequences and render a static representation close to what users see in a real terminal.

Installation

pip install erbsland-ansi-convert

Quick Start

from pathlib import Path
from erbsland.ansi_convert import Terminal

terminal = Terminal(width=120, height=40, back_buffer_height=2000)
terminal.write(Path("path/to/output.log").read_text())

Path("out.txt").write_text(terminal.to_text())
Path("out.ansi.txt").write_text(terminal.to_ansi())
Path("out.visible-esc.txt").write_text(terminal.to_ansi(esc_char="␛"))
Path("out.html").write_text(terminal.to_html(class_prefix="my-ansi"))

For terminal capture files, prefer writeFile() to preserve carriage returns:

terminal = Terminal()
terminal.writeFile("capture-via-script-cmd.txt")

If your input text already normalized carriage returns to newlines, you can enable the progress-line collapse heuristic on write():

terminal.write(text, collapse_capture_updates=True)

Command Line

Installing the package also installs the erbsland-ansi-convert command:

erbsland-ansi-convert [-f/--format (text|ansi|html)] [-c|--collapse] [-C|--no-collapse] [-o/--output <file>] [<input file>|-]

• -f, --format: output format (text, ansi, html), default ansi
• -o, --output: write output to file, default stdout
• -c, --collapse: enable collapse heuristic
• -C, --no-collapse: disable collapse heuristic
• <input file>: input capture file, or - for stdin

Supported Terminal Features

• Control characters: BEL, BS, HT, LF, VT, FF, CR, DEL
• Cursor controls (CSI A/B/C/D/E/F/G/H/f, ESC M, save/restore variants)
• Erase functions (CSI J, CSI K including mode 3J for saved lines)
• SGR text styles (bold, dim, italic, underline, blink, reverse, hidden, strike)
• Basic + bright 8 ANSI colors for foreground/background
• Common private modes: cursor visibility (?25) and alternate buffer (?47, ?1049)

Unknown sequences can optionally be reported as warnings.

HTML Output Model

to_html() produces:

<div class="{prefix}-block"><pre>...</pre></div>

Text styles are represented with flat span classes such as:

• {prefix}-bold
• {prefix}-red
• {prefix}-background-blue

Spans are reopened only when style actually changes to keep output compact and easy to style.

Development

Install development dependencies:

pip install -r requirements-dev.txt

Run tests:

pytest

License

Copyright (c) 2026 Tobias Erbsland / Erbsland DEV (https://erbsland.dev)

Licensed under the Apache License, Version 2.0. See LICENSE for details.