Image Resizer
File ToolsResize to exact pixels or a ready preset, including the Indian passport photo size.
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35 × 45 mm at 300 dpi
Result
Add an image to resize it. It is processed here in your browser and never uploaded.
Crop to fill keeps the proportions and trims the overflow. Squash to fit forces the exact box and will distort the picture — for a passport photo, use crop.
How this is calculated
pixels from millimetres px = (mm / 25.4) x dpi Indian passport photo 35 mm -> (35 / 25.4) x 300 = 413 px 45 mm -> (45 / 25.4) x 300 = 531 px Crop to fill keeps the aspect ratio and trims the overflow. Squash to fit forces the exact box and distorts the picture.
How it works
Resizing changes the pixel dimensions of an image. The only real decision is what happens when the shape you want does not match the shape you have — and that is where most online resizers quietly get it wrong by stretching.
Crop to fill scales the image until it covers the target box, then trims whatever hangs over the edges. Proportions are preserved and nothing is distorted; you just lose some of the edges. Squash to fit forces the image into the exact box regardless of shape, which will make faces look wide or tall. For a passport photo or any picture of a person, always crop.
Document sizes are specified in millimetres at a print resolution, not in pixels, so they need converting. An Indian passport photo is 35 × 45 mm, and at the 300 dpi that photo booths and print shops expect, that is 413 × 531 pixels. Getting this wrong is the most common reason an application photo is rejected.
Enlarging cannot add detail that was never captured. Scaling a 400-pixel image up to 1600 pixels gives you a 1600-pixel image that looks soft, because the extra pixels are interpolated guesses. The tool warns you when you are doing it.
Worked example
A 4000 × 3000 photo into an Instagram square post
- target = 1080 x 1080, aspect ratio 1:1
- source is 4:3, wider than the target
- crop height stays 3000, crop width becomes 3000
- centre the crop: x offset = (4000 - 3000) / 2 = 500
- scale the 3000 x 3000 crop down to 1080 x 1080
1080 × 1080, undistorted, with 500px trimmed from each side
How to use it
- Pick a preset for a known size, or set exact pixels, or scale by percentage.
- For exact pixels, leave the aspect lock on to keep proportions — turn it off only if you genuinely want a specific non-matching size.
- Choose crop to fill for photos of people or anything where distortion would be obvious.
- Add your image, check the preview, and download.
What this tool does not do
- It resizes one image at a time. For bulk work, use the image compressor, which handles batches.
- Enlarging cannot recover detail. The warning appears for a reason.
- It does not do face detection, so crops are centred or positioned by the aspect ratio rather than by subject.
Frequently asked questions
What size is an Indian passport photo in pixels?
413 × 531 pixels at 300 dpi, which is the digital equivalent of the required 35 × 45 mm. The preset here uses exactly that.
How do I resize an image without losing quality?
Scaling down is essentially lossless in perceived terms — you are discarding detail you no longer need. Scaling up always looks softer, because the extra pixels are interpolated. Keep the quality setting at 90% or above when downscaling.
What is the difference between crop to fill and squash to fit?
Crop to fill preserves proportions and trims the overflow, so nothing looks stretched. Squash to fit forces the exact dimensions and distorts the image if the shapes do not match. Use crop for anything with a face in it.
Are my images uploaded to a server?
No. Resizing happens entirely in your browser. No image data is sent over the network, and nothing is stored anywhere but your own device. The only requests the page makes once you use it are small ones recording that the tool was used.
How do I convert millimetres to pixels?
Divide the millimetres by 25.4 to get inches, then multiply by the dpi. At 300 dpi, 35 mm is (35 / 25.4) × 300 = 413 pixels.
Why does my enlarged image look blurry?
Because the detail was never there. Enlarging invents pixels by interpolating between existing ones — no tool can recover information the camera did not capture. Start from a larger original if you can.
What size should Instagram and other social images be?
Instagram posts are 1080 × 1080, stories 1080 × 1920, YouTube thumbnails 1280 × 720, LinkedIn banners 1584 × 396. All are available as presets here.
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Last updated 3 September 2026.