Image to A4 Size Converter: Resize Photo, JPG or PNG to A4 Paper
Drop in any photo, JPG, PNG or scanned document and resize it to exact A4 paper dimensions (21 × 29.7 cm / 2480 × 3508 px at 300 DPI) in your browser—nothing gets uploaded to a server.
Dimensions: 21 × 29.7 cm
Resize to A4 Paper Size
Drag and drop your images here
or click to browse your files
Supports JPG, PNG, WebP, and GIF (100% browser-based)
What is A4 paper size
A4 is the standard paper size used almost everywhere outside the US and Canada, including India, Pakistan and Bangladesh. It measures 21 by 29.7 centimetres, or 8.27 by 11.69 inches. If you've ever had a photo or scanned document come out the wrong shape when you tried to print it, it's usually because the image wasn't sized to match A4 in the first place. That's what this tool fixes.
A4 size in cm, mm, inches and pixels
Different tasks call for different units, so here's A4 broken down for all of them. The pixel values change depending on DPI (dots per inch), which matters if you're printing versus just viewing on screen.
| Unit | Width | Height |
|---|---|---|
| Centimetres (cm) | 21 cm | 29.7 cm |
| Millimetres (mm) | 210 mm | 297 mm |
| Inches | 8.27 in | 11.69 in |
| Pixels at 72 DPI (screen) | 595 px | 842 px |
| Pixels at 150 DPI (draft print) | 1240 px | 1754 px |
| Pixels at 300 DPI (high-quality print) | 2480 px | 3508 px |
If you're printing the image, go with 300 DPI so it doesn't come out blurry. 72 DPI is fine if the image is only going to be viewed on a screen or shared online.
How to convert an image to A4 size (Portrait or Landscape)
- Upload your photo, JPG, PNG, WebP, or GIF file using the upload area above.
- Portrait A4 (default): Pre-set to 21 × 29.7 cm (2480 × 3508 px at 300 DPI). For Landscape A4, enter 29.7 cm width and 21 cm height (3508 × 2480 px).
- Fitting vs. exact frame: Enable Lock aspect ratio if your source photo has a different shape (such as 4:3 or 16:9) and you want to avoid stretching, or keep it unlocked to fill the full 21 × 29.7 cm A4 canvas.
- Click Resize Image to generate your 300 DPI A4 file locally in your browser.
- Download the finished file. When printing, select “Actual Size” or “100% Scale” in your print dialog.
Converting different file types to A4
JPG to A4
The most common format for phone camera photos and scanned documents. Upload your JPG, the tool detects it automatically, no conversion step needed first.
PNG to A4
Works the same way as JPG. If your PNG has a transparent background, that transparency is kept unless you choose to add a white background before resizing.
JPEG to A4
JPEG and JPG are the same format, just different file extensions, so this tool handles both identically.
Photo to A4
If you're resizing a personal photo (a portrait, a document scan, an ID photo) for printing or for a form that asks for A4-sized attachments, use the aspect ratio lock so your subject doesn't get stretched or squeezed.
Tips for best results
- Start with the highest-quality version of your original image. Resizing up from a small, blurry photo won't add detail back in.
- Keep the aspect ratio locked unless you specifically want to stretch the image to fill the full A4 frame.
- If the image is going to print, aim for 300 DPI (2480 x 3508 px) so text and details stay sharp.
- A plain, uncluttered background works best if the image is going on an official document or form.
Other Free Image Tools
- Resize Image in CM Enter any custom centimeter width and height at 300 DPI for non-standard print sizes
- Resize Image by Pixels Set exact pixel dimensions (such as 2480 × 3508 px or 595 × 842 px) directly
- Image Compressor Compress large A4 document scans to 300 KB or 100 KB for portal uploads
- Image Format Converter Convert between JPG, PNG, WebP, and static GIF formats in your browser
- Passport Size Photo Maker Crop and resize photos to 3.5 × 4.5 cm (300 DPI)
- ID Card Size Converter Resize images to standard ID card dimensions (8.56 × 5.4 cm)
Frequently asked questions
What size is A4 in cm?
A4 is 21 cm wide and 29.7 cm tall in portrait orientation (or 29.7 × 21 cm in landscape).
How do I resize a JPG to A4 size online?
Upload your JPG using the tool above, keep the pre-selected 21 × 29.7 cm A4 preset (or switch to 29.7 × 21 cm for landscape), click Resize Image, and download.
What is A4 size in pixels?
At 300 DPI (standard print resolution), A4 measures 2480 × 3508 pixels. At 150 DPI it is 1240 × 1754 pixels, and at 72 DPI (screen display) it is 595 × 842 pixels.
How do I resize an image to A4 without stretching or distortion?
Turn on “Lock aspect ratio” in the resize settings if your photo does not match the 1 : 1.414 A4 ratio, or enter 29.7 cm width by 21 cm height for landscape scans. Starting with a high-resolution original image ensures fine text and details stay sharp at 2480 × 3508 px.
Does this tool upload my image to a server?
No. All resizing happens directly in your browser using JavaScript. Your image never leaves your device.
Is this free to use?
Yes, completely free, no signup and no watermark on the downloaded file.