◈ Contrary Convertor

Local-first file conversion, download, and post-processing. 50+ formats. Zero uploads. Zero limits.

Contrary Convertor is a free, open-source desktop app that converts, downloads, and post-processes files completely locally — no cloud, no subscriptions, no file size caps, no account. Drop in a file, pick an output format, convert. That's it.

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⬇️ Download

Platform	File	Link
🪟 Windows	.exe installer (NSIS)	→ Releases
🍎 macOS	.dmg disk image	→ Releases
🐧 Linux	.AppImage (portable)	→ Releases

No installation required for AppImage — just chmod +x and run.
Windows installer bundles everything. Double-click and go.

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✨ Features at a Glance

🖼️ Image Conversion

• Formats: JPG · PNG · WebP · AVIF · GIF · TIFF · BMP · ICO · SVG
• Auto EXIF rotation — images never come out sideways
• Handles truncated or malformed images gracefully (failOnError: false)
• Quality presets: Lossless · High · Medium · Custom (manual slider)
• Resize by width/height with aspect-ratio awareness

🎬 Video Conversion

• Formats: MP4 · WebM · MOV · AVI · MKV · GIF · FLV · WMV
• H.264 + yuv420p + -movflags +faststart baked in for maximum compatibility
• Platform compatibility fix mode — rewraps and re-encodes for specific targets
• Extract audio from any video (MP3, WAV, FLAC, OGG, AAC, Opus)
• Framerate and resolution controls

🎵 Audio Conversion

• Formats: MP3 · WAV · FLAC · OGG · AAC · Opus
• Proper codec mapping per format (libmp3lame, pcm_s16le, flac, libvorbis, aac, libopus)
• Bitrate control

📄 Document Conversion

• PDF: → HTML · TXT · extract images · extract fonts · watermark
• DOCX/DOC/ODT: → PDF · HTML · TXT · extract images · extract text
• HTML: → PDF (via headless Puppeteer) · PNG screenshot
• Markdown: → HTML

📊 Data & Config

• JSON ↔ CSV ↔ XML ↔ YAML ↔ TOML ↔ .env — bidirectional, all combinations
• XLSX ↔ CSV · JSON · Excel
• Nested object auto-flattening for .env export

🗜️ Archives

• ZIP, TAR, GZ — compress and extract
• Game archives: .pak (Unreal 4/5) · .rpf (GTA V / RDR2) · .wad (Doom) · .obb (Android)

🔤 Fonts

• TTF ↔ OTF conversion via opentype.js
• Font metadata extraction (family, designer, glyph count, version, license)

🧊 3D Models

• OBJ → GLB · GLB → OBJ · FBX → GLB

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⬇️ URL Download Mode

Click "Want to download a link?" below the dropzone to switch to download mode. Paste any URL and hit download.

Supported Sources

Source	Method	Formats
YouTube	yt-dlp (auto-installed)	MP4 (1080p/720p/480p/360p/Best) · MP3
Spotify	spotdl (auto-installed)	MP3 @ 320k
Instagram	yt-dlp	MP4 · MP3
TikTok	yt-dlp	MP4 · MP3
Twitter / X	yt-dlp	MP4 · MP3
Facebook	yt-dlp	MP4 · MP3
Twitch	yt-dlp	MP4 · MP3
Reddit	yt-dlp	MP4 · MP3
Vimeo	yt-dlp	MP4 · MP3
SoundCloud	yt-dlp	MP3
Direct links	Multi-threaded downloader	Any file type

Notes:

• yt-dlp is downloaded automatically on first use — no manual setup needed.
• Spotify downloads work via spotdl, which is silently pip-installed on first use (uses the bundled Python if Python isn't on your system).
• Pasting a Spotify URL automatically locks the format picker to MP3.
• Direct link downloads support configurable parallel threads (1–16) for faster large-file downloads.
• Real-time progress shows percent, MB/s speed, and downloaded/total size.

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🤖 AI & Post-Processing Features

🖼️ AI Background Removal

• Select any image → choose "Remove BG" from the dropdown
• On-device AI subject detection — uses ONNX/WASM (@imgly/background-removal-node), nothing leaves your machine
• Mask editor — paint/erase canvas overlay to refine edges:
  • 🖌️ Brush — paint areas to keep
  • 🧹 Eraser — remove from mask
  • Adjustable brush size (5–80px), crosshair cursor
• Output: filename_removedbg.png (transparent PNG)
• AI model (~50MB) downloads once on first use, then cached

🔊 AI Background Noise Removal (2-pass)

• Select any audio or video file → choose "BG Noise Removal" under Post Process
• Pass 1 (DSP): double afftdn + anlmdn + low-shelf equalizer via FFmpeg
• Pass 2 (AI): DeepFilterNet speech enhancement model
• DeepFilterNet is silently auto-installed via pip on first use
• Falls back gracefully to Pass 1 if DeepFilterNet is unavailable
• Works on single files and bulk batches
• Output: filename_denoised.ext

📝 PDF Text Extraction + OCR

• Full text extraction page-by-page via pdfjs
• Where images exist in the PDF: [Insert Image Here] placeholder is inserted
• OCR for images — Tesseract.js extracts text from JPG, PNG, WebP, BMP, TIFF, GIF, AVIF
• pdf-lib fallback parser for encrypted/complex layouts

🔖 PDF Watermark

• Diagonal text watermark stamped across every page
• Adjustable opacity (0.00–1.00, default 0.15)
• Custom watermark text input
• Output: filename_watermarked.pdf

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📦 Bulk Mode

• Drop multiple files at once for batch conversion
• Right-click the dropzone → multi-file selection dialog
• Common output formats computed from intersection of all files' supported formats
• Per-file progress reporting and individual success/failure history entries
• Works with all conversion types including noise removal and watermarking

📋 Clipboard Paste

• Ctrl+V to paste files directly into the app
• Works with files copied from Explorer and screenshots from clipboard
• Clipboard images are saved to temp and loaded automatically

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⚙️ Settings

Open with the ⚙ gear icon in the title bar:

Setting	Description
Download Threads	Parallel connections for direct link downloads (1–16)
yt-dlp Quality	Default video quality: Best · 1080p · 720p · 480p · 360p · Audio Only

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🛠️ Tech Stack

Library	Purpose
Electron	Desktop shell
fluent-ffmpeg + ffmpeg-static	Video / audio processing
sharp	Image conversion
pdf-lib	PDF manipulation & watermarking
pdfjs-dist	PDF text extraction
mammoth	DOCX → HTML/TXT
puppeteer	HTML → PDF / PNG
tesseract.js	OCR for images
@imgly/background-removal-node	AI background removal
yt-dlp	Video/audio downloading
spotdl	Spotify downloading
DeepFilterNet	AI noise removal
file-type	Magic byte file detection
opentype.js	Font conversion
node-stream-zip	Archive handling

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🚀 Run from Source

git clone https://github.com/AroseEditor/Contrary-Convertor.git
cd Contrary-Convertor
npm install --legacy-peer-deps
npm start

🏗️ Build

# Windows installer (.exe)
npx electron-builder --win nsis

# macOS DMG
npx electron-builder --mac dmg

# Linux AppImage
npx electron-builder --linux AppImage

Output goes to dist/. A build-release.bat is included for Windows convenience.

GitHub Actions

A unified release workflow (.github/workflows/release.yml) builds all three platforms in parallel, auto-extracts the version from package.json, parses the matching section from updates.md as release notes, and drafts a GitHub Release. Trigger it manually from the Actions tab.

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🤝 Contributing

PRs welcome. Open an issue first for major changes.

1. Fork the repo
2. Create your branch: git checkout -b feature/my-feature
3. Commit: git commit -m 'Add: my feature'
4. Push: git push origin feature/my-feature
5. Open a Pull Request

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📜 Changelog

See updates.md for the full version history.

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📄 License

MIT © Arose Editor

If this saved you time, you can support development via UPI — DM on Discord: ayush.ue5