Image Format Converter
Batch-convert PNG, JPG and WebP, resize images, and control JPEG backgrounds locally.
This tool runs entirely in your browser. Your data is never uploaded, never stored, and never leaves your device.
Batch-convert images to PNG, JPG or WebP locally, with maximum-edge resizing, explicit JPEG backgrounds and a per-file conversion report.
How to use it
- 1Add supported image files and select the output format.
- 2Set the compression quality, maximum edge and JPEG background.
- 3Process the batch, inspect each file's result, then download outputs and the conversion report.
What happens to your data
Files are decoded and re-encoded sequentially on your device, never uploaded. Canvas output is a new still image: original metadata, editable layers, colour profiles and animation are not retained, so keep your source files.
Last updated September 2026
Convert a batch of images to PNG, JPG or WebP without uploading them, with a per-file record of what succeeded. Set an output format, quality and maximum edge length, then process files sequentially so one unsupported image does not have to discard every good result. Download individual outputs and a conversion report.
Transparent PNG to JPG conversion needs a background decision. JPEG cannot store alpha, and merely passing transparent pixels to an encoder can produce a dark background instead of the white or coloured canvas you expected. Here the selected background is drawn before JPEG output. PNG and WebP remain appropriate when transparency is required.
A new extension is not proof of a new format. The workflow checks the encoder's actual output type so a browser that cannot write the requested format does not silently produce PNG bytes named .webp. Canvas conversion re-encodes the image: it is not a lossless byte copy, a metadata-preserving export or an animation converter.
How it works
Each source is decoded into local pixels, resized to the chosen maximum edge while preserving aspect ratio, and drawn to a bounded canvas. The browser encodes that canvas as the selected format. Outputs keep their own size, name and success state, making it possible to identify a failed file rather than trusting one batch-wide success message. A maximum-edge setting reduces larger images rather than stretching smaller ones.
JPEG and WebP quality affect compression; PNG uses a different lossless encoding model, so a quality slider is not a promise to shrink PNG by the same amount. Add up to 30 files, at most 150 MB total. Each input is limited to 30 MB and 40 million pixels; output is limited to an 8,192-pixel edge and 16 million pixels. The maximum edge defaults to 4,096 and must be set. Decode or encoder failures are reported. Metadata such as EXIF, orientation records and colour profiles is not copied into the new file; browser-decoded appearance is what is exported. Animated sources produce a still image, not an animated output.
Worked example: resize without stretching
- Input
- An image 6000 × 4000 pixels. Maximum edge: 2000.
- Result
- The exported dimensions are 2000 × 1333 pixels.
Aspect ratio is retained with integer pixel rounding. JPEG output fills transparent regions with the selected solid background.
Common use cases
- Batch-converting product pictures into a consistent web format
- Converting transparent PNG files to JPG with an explicit background
- Resizing oversized images to a maximum edge before export
- Reviewing a conversion report to find unsupported or failed files
Frequently asked questions
Can I batch-convert images without uploads?＋
Yes. Add supported local images, set the format and options, and process the batch. Results are created on your device, with an individual success or error entry for each file.
Why does my transparent PNG need a background for JPG?＋
JPG has no transparency channel. Select the background colour that should replace transparent pixels, or choose PNG or WebP when transparency must remain.
Is converting JPG to PNG lossless?＋
PNG stores its newly decoded pixels losslessly, but it cannot recover detail already lost in the original JPEG. The complete conversion is still a decode-and-re-encode operation, not a restoration of the original photograph.
Does the image converter preserve EXIF and colour profiles?＋
No. Canvas exports do not copy original metadata, layers or colour profiles into the new file. Keep the original when those records matter, and inspect colour appearance before publishing.
Will a maximum edge setting upscale a small picture?＋
No. It limits larger dimensions while preserving aspect ratio; a source already within the limit does not need enlargement. Upscaling would not recover missing source detail.
Will GIF or WebP animation remain animated?＋
No. This is a raster still-image conversion workflow. A browser-decoded frame is exported; use an animation-specific tool when all frames and timing must be preserved.
Standards and limitations
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