About Constly
Constly renders Markdown in place as you type. Headings, bold, lists, tables, KaTeX math and Mermaid diagrams read as finished text, and the raw marks show only on the line your cursor is on.
Plain text is the document. The rendered view is a projection over it, so saving touches only the bytes you changed: Constly never re-wraps, reorders or normalises Markdown you left alone. Your line endings, byte-order mark and trailing spaces all survive. Every release is checked against a corpus of real files.
Tables are an editable grid. Click a cell and type, Tab across, Enter for the next row, and the source reflows to aligned pipes when you leave. There is a command palette, quick-open, workspace search, tabs, session restore, a document outline, focus and typewriter modes, real modal Vim with a status bar, and a git gutter diff against HEAD.
Nothing phones home. No account, no telemetry, no server to reach. Remote images stay unloaded until you allow them, and Constly never needs the network to open, edit or save a file. Local version history is off by default; turn it on and it snapshots each document as you save, on your disk.
Export to PDF, self-contained HTML, Word, ODT, RTF, LaTeX or EPUB. Import from Word and HTML. Opens .md, .markdown and .mdx.
The installer installs per user, so it needs no administrator rights. Constly is free to use with nothing gated: no expiry, no watermark, no locked exports. After two weeks a weekly reminder appears, and a one-time licence for up to three devices retires it. Pricing is on constly.com.
