Document format converter
Convert TXT, Markdown, HTML, and CSV up to 5 MiB locally. CSV is capped at 100,000 rows/1,000 columns/200,000 cells, HTML at 100,000 nodes/depth 100, and output at 10 MiB.
Complex formatting may be lost, and invalid input produces no download.
How to use this tool
Process TXT, Markdown, HTML, or CSV files up to 5 MiB locally in the browser and expose only genuinely supported text or table outputs.
Convert documents seamlessly between Markdown, HTML, and plain text. Preserves headers, tables, code blocks, and formatted lists with CommonMark and GitHub Flavored Markdown (GFM) standards.
💡 3 Quick Steps to Get Started
Paste your Markdown notes, HTML markup, or raw formatted text.
Choose Markdown-to-HTML or HTML-to-Markdown conversion.
Inspect formatted rendering live and copy the converted output with one click.
When it helps
The exact matrix is TXT → Markdown/HTML, Markdown → TXT/HTML, HTML → TXT/Markdown, and CSV → TXT (flattened text)/Markdown/HTML/TSV (tabular text).
How it works
The source comes from the extension, decoding is strict, and quoted CSV fields are parsed correctly; the tool never invents a table or offers same-format output.
Worked example
Upload a CSV containing quoted commas and newlines, review the table, and download Markdown; malformed input produces no partial result.
Limits and data handling
Input over 5 MiB, CSV over 100,000 rows/1,000 columns/200,000 cells, HTML over 100,000 nodes/depth 100, or output over 10 MiB is rejected. Only the stated directions and limited Markdown/HTML subsets are supported; complex styling, scripts, layout, and document objects are not preserved.
Files and text never leave the browser and are not stored. Analytics contains only tool, category, locale, action, and normalized status—not content or filenames.
Document Formats, Office OpenXML & Cross-Platform Fidelity Guide
1. Open Document Standards: Office OpenXML vs. ODF
Modern document formats package compressed XML manifests: DOCX under ISO/IEC 29500 (OOXML) and ODT under ISO/IEC 26300 (ODF). Structural parsers translate XML node trees (paragraphs, run styles, table cells) across schemas.
2. Typography and Table Layout Fidelity Preservation
Layout preservation resolves font-fallback metrics and paragraph margin definitions to prevent unintended text-flow pagination anomalies across different operating systems.
3. Sandboxed Privacy Lifecycle
Conversion payloads execute in memory-isolated sandbox containers, deleting document buffers immediately upon delivery.
Feedback
How can we improve this tool?
Send a suggestion or bug report for this tool.
FAQ
What inputs does Document format converter accept?
One input file up to 5 MiB is accepted: .txt, .md, .markdown, .html, or .csv, decoded as UTF-8 or BOM-marked UTF-16LE/UTF-16BE. CSV is limited to 100,000 rows, 1,000 columns, and 200,000 cells; HTML to 100,000 nodes and depth 100; output to 10 MiB.
How does Document format converter produce its result?
Decoding, parsing, and conversion stay in the browser. HTML output escapes user text, and uploaded HTML is never executed as a web preview.
What limitations apply to Document format converter?
Input over 5 MiB, CSV over 100,000 rows/1,000 columns/200,000 cells, HTML over 100,000 nodes/depth 100, or output over 10 MiB is rejected. Only the stated directions and limited Markdown/HTML subsets are supported; complex styling, scripts, layout, and document objects are not preserved.
How does Document format converter handle data?
Files and text never leave the browser and are not stored. Analytics contains only tool, category, locale, action, and normalized status—not content or filenames.
