Code Snippet Image Builder

How to use Code Snippet Image Builder

Turn plain code or other short source text into an actual PNG with a measured monospace layout, title and optional line numbers. Prepare a readable image for a document or message without sending private source to a remote renderer. This local Canvas layout treats every character as text, measures each expanded line and refuses oversized output before allocating the final raster.

1. Provide optional utf-8 source file, plain source text, optional image title, first displayed line number.
2. Choose the supported mode and run the tool. Review its assumptions and any reported errors.
3. Copy the result or download a separate output; reset to clear the current form.

Good to know

• One strict UTF-8 source up to 16,000 bytes and 120 logical lines, including an empty final line. A file takes precedence over pasted source. CRLF, CR and LF each separate one line and are counted in the report. An initial BOM is retained as a text character. Other C0/C1 controls are refused.
• Plain text is drawn with Canvas fillText. Supplied JavaScript, HTML, SVG, CSS and template syntax are never parsed as active code, mounted, fetched or executed. This is not a syntax highlighter, terminal emulator or exact editor screenshot.
• Select a fixed 12–24 px font size, a 2/4/8 Unicode-scalar tab stop, optional line numbers beginning at an exact plain integer 1–999,999, and a single-line title up to 160 UTF-8 bytes. Tabs expand before drawing. Combining characters, shaping, bidirectional text, emoji and fallback fonts can differ across systems.
• Every expanded line and title is measured with the browser’s current monospace fallback before the final canvas is allocated. Lines do not automatically wrap or scale. Output is at most 4,096 pixels per side and 4,000,000 pixels; larger measured text refuses instead of being clipped or truncated.
• The fixed opaque theme, padding, line spacing and gutter are included in the PNG. Native measurement and glyph rendering depend on the actual browser fonts; no embedded font or cross-device pixel identity is promised. Keep important source available as accessible text alongside any image.
• The PNG encode has a 5-second wait and an 8 MiB output limit. Native Canvas/font/encoder work cannot be forcibly interrupted; source, line and pixel caps bound the requested work. Canvas resources are reset after success or failure. The original file is never modified or uploaded.
• Structured text output is limited to 500,000 characters. Reduce the supplied source when that separate output budget is exceeded.
• Inputs are processed on this device and are not automatically saved or uploaded.