Drop files here or click to browse, or paste (Ctrl/⌘+V) — images & SVG, CSV, Excel, JSON, Markdown, HTML, XML, audio, ZIP/TAR/GZ, anything

Supported conversions

Images — PNG, JPG, WEBP, GIF, BMP, SVG, ICO (AVIF where your browser decodes it)	→	PNG, JPG, ICO favicon, PDF (+ WEBP/AVIF in browsers that can encode them)
Several images	→	one multi-page PDF
CSV / TSV (comma, semicolon, or tab — auto-detected)	→	JSON, Excel (.xlsx), CSV/TSV, Markdown table
Excel (.xlsx)	→	CSV, JSON, Markdown table (first sheet)
JSON	→	CSV, TSV, Excel, NDJSON, Markdown table, pretty-print, minify
NDJSON / JSONL	→	JSON array, CSV
Markdown	→	HTML page, plain text, CSV (first table)
HTML	→	Markdown, plain text
XML	→	JSON
Audio — MP3, OGG, M4A, FLAC…	→	WAV (16-bit PCM, ready for any editor)
ZIP, TAR, TAR.GZ	→	extracted files
GZ	→	decompressed file
Text with broken encoding	→	clean UTF-8 (fixes "Ã©" mojibake)
Any file at all	→	Base64 text, GZIP
Base64 text (.b64)	→	the original file

How this protects your privacy

The usual "free online converter" works by uploading your file to someone's server — your spreadsheet, your photos, your notes, sitting in a stranger's logs. This one doesn't have a server. The file is read, converted, and re-packaged entirely inside your browser tab; you can pull the network cable mid-conversion and nothing changes. No accounts, no tracking of file names or contents.

Honest limitations

Converting to JPG is lossy and flattens transparency onto white. Converting to PNG is lossless but files can grow.
Image conversion is also a metadata strip — the output is rebuilt from pixels, so EXIF/GPS does not survive. (For inspecting what's in there first, use Photo Cleaner.)
The Markdown renderer covers everyday markdown (headings, lists, links, code blocks, quotes) — not the full CommonMark spec. Same spirit for HTML→Markdown.
CSV→JSON assumes the first row is a header. JSON→CSV/Excel needs an array of flat objects or arrays; deeply nested values are embedded as JSON strings.
Excel output is a minimal clean workbook (one sheet, no formatting). Excel input reads the first sheet's values — formulas come through as their last computed value.
Audio is one-way: browsers can decode MP3/OGG/M4A but ship no encoders, so WAV is the output. WEBP/AVIF output appears only in browsers that can actually encode them.
Encrypted ZIP entries are skipped and reported. Extracted files keep their names but not their folder structure.
Very large files are limited by your browser's memory.

Part of K-Engine Local Tools — free, privacy-respecting utilities that run on your device. Open source; every converter is hand-written and small enough to audit over coffee. MIT licensed, from the K-Engine workshop · download the source.