A fast, lightweight, and 100% offline batch image converter and resizer for Windows.
Formatix Image Converter is a powerful desktop application designed to batch convert, resize, and optimize images in just a few clicks. Whether you need to convert Apple's HEIC formats to JPG, turn SVG vector graphics into PNG, or compress heavy images into next-generation AVIF and WEBP formats, this program handles it all instantly.
No file limits, no internet connection required — everything happens locally, with zero uploads and a strictly ad-free experience.
- Why Formatix Image Converter?
- Key Features
- Requirements
- Installation & Running
- Supported Input Formats
- Output Formats & Specifications
- Settings & Configuration
- FAQ
- Support the Project
- License
✅ 100% offline — images never leave your computer
✅ Portable & self-containedd — no installation, no registry entries, just a single .exe you can run from anywhere
✅ No plugins needed — works out of the box, no extra downloads or setup
✅ Free for everyone — including commercial use, licensed under GPL-3.0
✅ Open source — auditable, no hidden telemetry, no ads, ever
✅ Modern UI — dark and light theme, drag & drop, clean interface
✅ Popular Conversions Supported — browse all available formats
- Batch Processing — convert, resize, and optimize hundreds of images in a single operation
- 8 Output Formats — export to AVIF, WEBP, JPEG, HEIC/HEIF, PNG, BMP, TIFF, and ICO
- Multi-threaded Conversion — converts multiple images simultaneously for fast batch operations
- Advanced Image Resizer — 5 resize modes: proportional scaling, smart crop, and custom dimensions
- Color Profile Management — ICC-based color space conversion via Pillow ImageCms for high color accuracy
- Multi-size ICO Generation — automatically creates Windows icon packs
- Adjustable Quality Settings — fine-tune compression levels for JPEG, WEBP, AVIF, and HEIC, or set a target output file size (KB/MB) and let automatically find the best quality to fit within it
- Custom File Renaming — choose from built-in presets or use the custom template builder in Settings
- Drag & Drop — instantly add folders or individual files
- Smart Conversion Cache — automatically skips files already converted with identical settings to save time
- Safe Processing — features atomic file writes (prevents partially written output files) and overwrite protection
- Built-in Image Comparison — easily compare the source file with the processed result side-by-side
- Multilingual UI — 6 interface languages: English, Русский, Українська, Deutsch, Suomi, 中文
- Light & Dark Mode — switch between themes in Settings
- OS: Windows (if using the pre-compiled
.exestandalone app) - Python: 3.10+ (only required if running from source)
- Dependencies:
Pillow,pillow-heif,tkinterdnd2,resvg-py(only required if running from source)
Download the latest portable .exe from Releases and run it directly. No Python required, no installation, and no complex setup — just click and convert.
To run the script from the source code, you need Python 3.10+ and the necessary libraries.
- Install the required dependencies:
pip install Pillow pillow-heif tkinterdnd2 resvg-py- Make sure all project files are in the same folder:
| File | Description |
|---|---|
formatix.py |
Main app / entry point |
localization.py |
UI language strings & system language detection |
converter.py |
Image conversion & processing logic |
compare.py |
Before/after comparison window |
settings.py |
Settings and Donate dialog windows |
update.py |
Checking new version |
- Run the application:
python formatix.py| JPEG | PNG | WebP | AVIF | HEIC / HEIF | SVG | BMP | TIFF | GIF | ICO |
|---|---|---|---|---|---|---|---|---|---|
.jpg.jpeg |
.png |
.webp |
.avif |
.heic.heif |
.svg |
.bmp |
.tiff.tif |
.gif |
.ico |
| Format | Compression Type | Notes for Users |
|---|---|---|
| AVIF | Lossy (Adjustable) | Next-generation format; offers superior compression with high visual quality. |
| WEBP | Lossy (Adjustable) | Best size-to-quality ratio for modern web development. |
| JPEG | Lossy (Adjustable) | Standard universal format; RGBA transparency is auto-converted to RGB. |
| HEIC | Lossy (Adjustable) | High Efficiency Image Format, commonly used by Apple iOS devices. |
| PNG | Lossless (Fixed) | Ideal for graphics requiring perfect clarity and an alpha channel (transparency). |
| BMP | Uncompressed (Fixed) | Raw bitmap files with absolutely no compression. |
| TIFF | Lossless (Fixed) | High-fidelity format used for professional printing and archival storage. |
| ICO | Lossless (Fixed) | Windows icon container (automatically generates sizes up to 256×256 px). |
Settings are stored locally in ~/.formatix_image_converter_settings.json.
You can enable or disable settings persistence in the Settings window. When disabled, the application always starts with default values (note: the language preference is determined by the system language).
Q: Which format should I choose for maximum compression?
Use AVIF — it's the most modern format available. It delivers the smallest file sizes while maintaining excellent visual quality. Ideal for web, storage optimization, or sharing. At a quality setting of 85%, the file size is often 4× smaller than the original with no visible difference to the eye.
Q: Which format is best for web images?
WEBP is the go-to for general web use — it offers a great balance between file size and quality, and is widely supported by all modern browsers. If your target audience uses up-to-date browsers, AVIF is even better.
Q: Which format should I use if I need transparency (alpha channel)?
Use PNG (lossless, supports full alpha) or WEBP (lossy with alpha support). Avoid JPEG and BMP — they don't support transparency. JPEG will auto-convert RGBA to RGB.
Q: Can I convert SVG files?
Yes. SVG files are accepted as input and can be converted into raster formats such as PNG, JPEG, WEBP, AVIF, and others.
Q: Does it upload my images anywhere?
No. Everything is processed fully offline on your local machine. Your files are never uploaded, shared, or sent anywhere.
Q: What does the quality slider affect?
The quality setting applies to lossy formats: JPEG, WEBP, AVIF, and HEIC. Lossless formats (PNG, TIFF, BMP, ICO) ignore this setting and always output at full quality.
Q: How do I compare the original and converted image?
After conversion, click the Compare button — it opens a side-by-side view so you can evaluate quality and file size.
If Formatix Image Converter saved you time or effort, a small donation to support further development is always appreciated!
| Currency | Network | Address |
|---|---|---|
| BTC | Bitcoin | bc1q8ajkfe5zg26ugwthjlcjqtn06dveh3kehted90 |
| ETH / USDT / BNB | ERC-20 / BEP-20 | 0x08bDC7b9d6f400260973B73063Eb81c27A10f1e3 |
| USDT | TRC-20 | TU2RZTdh8p2fEt2hnKrUTAZNj8trfW6hYE |
| SOL | Solana | 4VAPnL62M7o8SwrYHhE8ZSpHqDM8qvkqCjL4EKaAFj58 |
| TON | Toncoin | UQBPQAbGEsyCGNEZAXZoUBOcaTYglXl9FAZSu-7gQdxE-k7O |
This project is licensed under the GPL-3.0 License.