InfyTool
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Image resizer

Pixels, percentages, centimetres or inches — with crop, rotate, DPI and a file-size target — batch resized with Lanczos quality, without uploading anything.

PNG, JPG, WebP, AVIF, GIF, BMP · or drop files anywhere in this box

No size limit · files are processed on your device and never uploaded · how it works

Advanced settings (optional)
Resize options
Resize by
px

Width, Height, Longest side and Percentage keep the aspect ratio; Fit keeps it inside a box; Exact sets both sides.

Unit & DPI

Switch to inches, cm or mm to size for print; the DPI converts them to pixels and is written into the file.

Rotate & flip
no rotation

Applies to every file; crop individual files from their row.

Upscaling
Output format

Keep the same format, or switch to WebP/AVIF for bigger savings.

Image quality
80

Lower values give smaller files but lower quality. 80 is a good balance for photos; 90+ for graphics with text.

Max file size
or

Optional. Set a limit such as 500 KB for upload forms; quality is reduced automatically to meet it.

Transparency

Transparent areas are filled with this colour, so the result has a solid background.

Runs in your browser. Files are never uploaded — you can go offline after the page loads.

How to use the Image Resizer

  1. Click “Choose Files” or drop your images into the box above. Whole folders work too.
  2. Adjust the Advanced settings if you need to, then click “Resize”.
  3. When the row shows Done, click “Download” — or “Download all” for a ZIP.

Easy to use

Drop files, pick options, download. Whole folders at once, no signup, no daily limit.

Best quality

The same engines the professionals use — SVGO, resvg, MozJPEG, libwebp, libavif — compiled to run in your browser.

Private & secure

Files are processed on your device and never uploaded. Close the tab and nothing remains anywhere.

How the resizer works

Choose how to resize — by width, height, longest side, percentage, fit-in-a-box or exact size, in pixels, centimetres, millimetres or inches — and drop images. Each file is decoded in your browser, resampled with a Lanczos3 filter in linear RGB (premultiplied alpha, so transparent edges stay clean), then encoded to PNG, JPG, WebP or AVIF at the quality you set. Batches run across several CPU cores in parallel and download as a ZIP. Nothing is uploaded.

Modes

  • Width / Height — set one dimension, the other follows the aspect ratio. The everyday choice.
  • Longest side — cap the bigger dimension regardless of orientation; ideal for mixed portrait/landscape folders.
  • Percentage — scale everything by the same factor.
  • Fit inside box — guarantee the result fits within a width and a height without cropping.
  • Exact size — set both dimensions. With the ratio locked (default) the second value follows the first image’s proportions; unlock it to allow stretching.

Platform sizes — Instagram, YouTube, LinkedIn, X, Facebook, Pinterest, Reddit, Discord and more — live in the Social Media Image Resizer, which places the picture in each frame with a fit/fill slider instead of forcing pixels.

Crop, rotate, print units and file-size targets

Every file in the list has a Crop button: pick a free box or an aspect ratio (square, 4:5, 16:9, 9:16, 3:1, custom), drag the handles or type exact pixel values, and the crop is applied before resizing. Rotate & flip apply to the whole batch — useful for a folder of sideways phone photos. Switch the unit to inches, cm or mm to size for print: the DPI you choose (300 for print) converts the measurement to pixels and, when “Write DPI into file” is on, is stored in the PNG or JPG so it opens at the intended physical size. Finally, Max file size lowers JPG/WebP/AVIF quality just enough to stay under a limit such as 500 KB — handy for upload forms — and tells you when a PNG cannot be squeezed that far.

Never upscale is on by default: an image smaller than the target is re-encoded but not enlarged, because upscaling only adds blur. Output dimensions are capped at 50 megapixels to keep the browser responsive.

Format and quality

Keep the source format, or convert while resizing — WebP is the best all-round choice for web use. Quality 80 suits photos; go higher for screenshots and text. File names get the new dimensions appended (photo-1280x853.webp) so originals are never confused with resized copies. For pixel-perfect icons at many sizes, render from vectors with SVG to PNG instead.

Frequently asked questions

Which resize mode should I use?

Width or Longest side for most cases — they keep the aspect ratio and give a predictable maximum size. Percentage is handy for a folder of mixed sizes. Fit inside box guarantees the image fits within both a width and a height. Exact size forces both dimensions (lock the ratio to avoid stretching, or crop first). For Instagram, YouTube, LinkedIn and other platform sizes use the Social Media Image Resizer, which places the image in each frame without distortion.

Why does the result look sharper than resizing in my browser or a CMS?

Most quick resizers use bilinear or a single-pass box filter, which blurs. This tool uses Lanczos3 resampling computed in linear RGB with premultiplied alpha — the same approach as Squoosh and professional image pipelines — so edges stay crisp and dark fringes do not appear around transparent shapes.

Does resizing reduce quality?

Downscaling discards pixels by necessity but does so cleanly; the output is then encoded at the quality you choose (default 80 for lossy formats, lossless for PNG). Upscaling cannot add detail — the tool blocks it by default ("Never upscale") so a 800 px photo asked for 1920 px is left alone rather than blurred.

Can I resize in centimetres or inches, or set a file size limit?

Yes. Switch the unit to cm, mm or inches and set the DPI (300 for print) — the pixel size is calculated and the DPI is written into PNG and JPG files. Set a maximum file size such as 500 KB and the tool lowers the JPG/WebP quality just enough to meet it.

Can I resize for Instagram, YouTube thumbnails or LinkedIn banners?

Use the Social Media Image Resizer: it shows your image in every platform frame at once with a fit/fill slider, so a landscape photo becomes a 4:5 post or a 4:1 banner without being stretched.

Social Media Image ResizerEvery platform size, fit or fill Image CompressorSmaller files, same look Image ConverterPNG, JPG, WebP, AVIF — any direction

Your files never leave your device

Most online converters upload your file to a server. InfyTool ships the actual encoders to your browser as WebAssembly instead, so processing happens inside your tab — faster for batches, and nothing to delete afterwards.

  • No upload, ever. Turn off Wi-Fi after the page loads and every tool keeps working.
  • No limits. No file-size cap, no queue, no watermark, no account.
  • Runs on your CPU. Batches use several cores in parallel; nothing is throttled.

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