Free Image Converter — Batch Convert Locally in Your Browser
widantoo is a free image converter that runs entirely in your browser — convert PNG, JPG, WebP, AVIF, HEIC and camera RAW with no upload, no watermark, and no limits. Works on desktop, tablet and mobile browsers — open and batch-convert instantly, fast and private.
How to convert image formats online (free, no upload)
Three steps — no software to install, everything processed locally in your browser.
Upload images
Drag onto the page or click to select — add multiple at once. Format is detected from file content, so even misnamed files are handled correctly.
Choose target format
Convert freely between PNG / JPG / WebP / AVIF / BMP. Expand to adjust quality and dimensions — defaults are safe and non-destructive.
Convert locally & download
One click to start — conversion runs entirely in your browser. Download individually or pack all results into a ZIP.
Supported image formats
Covers all major and modern formats — detected by file content, with clear conversion options at a glance.
Lossless with transparency support — ideal for icons and UI screenshots.
Lossy compression, small file size — the universal format for photos and the web.
Modern format — smaller than JPG / PNG at equivalent quality.
Next-gen format with high compression — great for performance optimization.
Default iPhone photo format — convert to widely compatible formats.
Camera raw files (CR2 / NEF / ARW / DNG…) — develop and export to JPG.
Uncompressed bitmap — excellent compatibility, large file size.
Animations and simple graphics with indexed color.
Batch convert images and download as a ZIP
No need to click one by one. Set your target format, convert in one click, then grab all results as a single ZIP.
- Add any number of images at once
- Each image can target a different format
- Failed files are flagged individually without stopping the batch
- Pack all results into a ZIP or download individually
Why browser-based conversion?
Privacy, speed, and freedom — your images never leave your device, and there are no barriers to use.
Private — images never leave your device
All conversion happens locally on your device — nothing is uploaded, stored, or transmitted to any server. Safe for sensitive photos and client files.
Completely free, no barriers
No account, no usage limits, no watermarks, no registration. Open and use — nothing stored in the cloud.
Works offline too
Local processing in the browser — once loaded, conversion continues even without an internet connection (PWA offline support).
Unlimited batch conversion
Convert as many images as you need at once. Failed items are flagged individually without stopping the batch — download all successes as a single ZIP.
Frequently asked questions
Converting to lossless formats (PNG / BMP) adds no quality loss. For JPG / WebP / AVIF you can set quality (default 80) — higher means better quality and larger file size. Note: converting a lossy format to lossless does not recover already-lost detail.
No. Widantoo adds no watermarks, requires no login, and places no limit on downloads — you get a clean output every time.
Single file limit is 100 MB; there is no hard cap on batch count. Selecting more than 20 files shows a warning that slower devices may take longer, but does not block you.
No. The entire conversion runs in your browser's local memory — nothing is uploaded, stored, or transmitted. You can disconnect from the internet and still convert to verify this.
PNG, JPG, WebP, AVIF, and BMP support bidirectional conversion. HEIC and camera RAW can be used as source formats to convert into the above. GIF / TIFF and others are being integrated and will be available soon.
Yes. Widantoo adapts to phones, tablets, and desktops — the layout adjusts automatically and conversion runs locally on whatever device you use.