Max 20 MB · 10 files
Output format
90%
Fit modeResize only
Resize
Resize Image Online: Any Size, No Cropping, Keep the Whole Photo
How to Convert Images Online
1Upload your image
Drag and drop or select up to 10 images. HEIC, PNG, JPG, WebP, AVIF and more are supported.
2Choose a fit mode
Pick Proportional to set a width and keep the ratio, or Fit with padding to set an exact width and height with the whole image preserved.
3Choose a size
Select a preset like 1920x1080 Full HD or 1080x1080 square, or enter a custom size. Optionally pick an output format.
4Download
Download your resized image instantly. No signup, no watermark.
Supported Image Formats
HEIC
Apple photo format used by iPhone and iPad. High quality with small file size.
HEIF
High Efficiency Image Format — same as HEIC, used on Apple devices.
WebP
Modern image format by Google. Up to 30% smaller than JPG with the same quality.
PNG
Lossless format that preserves every pixel. Best for screenshots and logos.
JPG
Universal format for photos. Supported everywhere, great balance between quality and file size.
GIF
Classic format for simple animations. Supports transparency and up to 256 colors.
BMP
Uncompressed bitmap format. Maximum quality but very large file size.
TIFF
Professional lossless format used in printing and photography.
AVIF
Next-gen format with excellent compression. Up to 50% smaller than JPG.
PPM
Portable Pixmap format used in Unix/Linux environments.
HDR
High Dynamic Range format storing extended brightness data.
FITS
Flexible Image Transport System used in astronomy and science.
PDF
Portable Document Format. Convert PDF pages to JPG, PNG or WebP images.
AVIF vs WebP vs HEIC vs JPG
Quick comparison to help you choose the right format
AVIF
- Size: Up to 50% smaller than JPG
- Browsers: Chrome, Firefox, Safari
- Transparency: ✓
- Best for: Web performance
WebP
- Size: 25-35% smaller than JPG
- Browsers: All modern browsers
- Transparency: ✓
- Best for: Web compatibility
HEIC
- Size: ~50% smaller than JPG
- Browsers: Safari only
- Transparency: ✓
- Best for: iPhone storage
JPG
- Size: Baseline
- Browsers: All browsers & apps
- Transparency: ✗
- Best for: Universal sharing
Frequently Asked Questions
How do I resize an image without losing quality?
Make it smaller, not larger. Downscaling with a high-quality algorithm (Convertify uses libvips with a Lanczos3 final pass) produces a result that's visually identical to the original at the new size. Enlarging an image past its original dimensions is what causes visible quality loss, because the missing detail can't be recreated.
How do I resize an image to a specific width in pixels?
Upload your image, enter your target width (or pick a preset like 1920, 1280, 800, or 640 pixels), and Convertify resizes it to exactly that width. The height is calculated automatically to keep your image's proportions.
Does resizing an image reduce its file size?
Yes, significantly. Because file size tracks the total pixel count, reducing the width cuts the file weight sharply. In our tests, resizing a 4.5 MB photo to 1920 pixels wide cut it to about 524 KB, an 88% reduction, and to 800 pixels brought it under 110 KB.
What's the difference between resizing and compressing an image?
Resizing changes the pixel dimensions (how wide and tall the image is). Compressing keeps the dimensions the same but reduces file weight by storing the pixels more efficiently. If your image's dimensions are already fine and you only need a smaller file, use compression. If the image is physically too large, resize it.
What width should I resize my image to for a website?
For full-width hero and banner images, 1920 pixels is the standard, and it matches the most common desktop resolution. For blog and article body images, 1200 pixels works well. For smaller in-content images, 800 pixels is usually enough.
Will resizing keep my image's aspect ratio?
Yes. In Proportional mode we resize by width and calculate the matching height automatically. In Fit with padding your image is scaled to fit exactly and the remaining space is filled with a background. Either way the proportions are preserved, your image is never stretched or squashed.
Can I set both width and height?
Yes. Choose Fit with padding, enter width and height, and the image is scaled to fit inside without cropping. The remaining space is filled with a background (transparent for formats with alpha, white for JPG).
Can I enlarge (upscale) an image with Convertify?
Convertify is built for making images smaller. Enlarging an image beyond its original size can't recover detail that was never captured, so the result would look soft or blurry. For genuine enlargement you'd need a dedicated AI upscaling tool.
What image formats can I resize?
JPG, PNG, WebP, AVIF, HEIC, HEIF, TIFF, GIF, BMP, PDF, PPM, HDR and FITS. Keep original is the default, so your image keeps its format unless you pick a different one. Need to convert only, without resizing? Try PNG to WebP, HEIC to JPG or one of our other converters.
Is it safe to upload my images?
Yes. Files are processed on our server and automatically deleted within a few hours. They're never shared or used for any other purpose, and there's no signup required.
How do I resize a photo to fit under an upload size limit?
Start by resizing to a smaller width, which alone usually brings large photos well under common limits. Our data shows a 4.5 MB photo drops to about 250 KB at 1280 pixels and around 107 KB at 800 pixels. If you need to stay at full dimensions but reduce weight, use compression instead.
Can I resize several images at once?
Yes. Upload up to 10 images at once and Convertify resizes them all in a single batch. You get a ZIP with the resized files.
What is the difference between Proportional and Fit with padding?
Proportional scales by one side (width) and calculates the other automatically to keep the ratio. Fit with padding places the whole image inside an exact width by height and fills the remaining space with a background, so nothing is cropped.
What background is used for padding?
A transparent background for formats that support alpha (PNG, WebP, AVIF, HEIC, HEIF, GIF, TIFF), and a white background for JPG and other formats without transparency. A custom color picker is on the roadmap.
Can I resize and convert to another format at the same time?
Yes. Pick a target format in the output selector and resizing plus conversion happen in one pass. If you only need to convert without resizing, use one of our dedicated converters like PNG to WebP or HEIC to JPG.
When should I use padding vs compress?
Padding when you need exact dimensions without cropping (for example a 1080x1080 square that fits your whole photo). Compress when you need a smaller file at the same dimensions.
How do I fit a photo into a 1080x1080 square without cropping?
Switch to Fit with padding, enter 1080 by 1080 (or pick the Instagram Square preset), and the whole photo fits inside the square with a background. Nothing is cropped.
How resizing works: proportional or fit with padding
Resizing changes your image dimensions while keeping the whole picture, unlike cropping which removes parts. Convertify offers two modes. Proportional: set a target width and the height is calculated automatically so the aspect ratio stays exact. Fit with padding: set a target width and height, and the image is scaled to fit inside with the remaining space filled with a background, nothing cropped. Your image keeps its original format by default (JPG stays JPG, PNG stays PNG), or convert to any of 14 formats in the same pass. Need to trim edges instead? Use Crop Image.
Fit vs crop vs stretch: what each does to your image
Fit with padding keeps your whole image and adds a background where the aspect ratio differs. Crop removes parts of the image to reach an exact ratio (use Crop Image). Stretch distorts the image to force exact dimensions. Convertify never stretches your photo.
Choosing a background for padding mode
When the target aspect ratio differs from your image, the extra space is filled with a background automatically. Convertify uses a transparent background for formats that support alpha (PNG, WebP, AVIF, HEIC, HEIF, GIF, TIFF) and a white background for JPG and other formats without transparency. Transparent works well for overlays and logos, a solid fill suits marketplaces and email attachments.
Save in the format you need: 14 output formats
Keep original is the default, so your file format never changes unless you want it to. Or convert in the same pass to JPG, PNG, WebP, AVIF, HEIC, HEIF, TIFF, GIF, BMP, PDF, PPM, HDR or FITS. Pick WebP or AVIF for smaller web files, PNG for lossless quality with transparency, JPG for universal compatibility. Need to combine several resized images into one document? Try images to PDF.
Resize or compress: which one do you need?
Before you resize, it helps to know whether you actually need smaller dimensions or a smaller file size, because they are not the same thing. If your goal is fewer pixels (for example, shrinking a 4284 pixel wide photo to 1920 pixels for a web banner), you are in the right place. If you need to keep the same dimensions but reduce the file's weight to fit an email or upload limit, that is compression: try compress JPG, compress PNG, or compress WebP instead. In practice resizing a large photo down also dramatically reduces its file size, often more effectively than compression alone, which is why most people uploading oversized camera photos only need this page.
Real data: how much file size drops at each width
We took 24 full resolution photos from an iPhone (4284 x 5712 pixels, averaging 4.5 MB each as JPEG) and resized them to common web widths through our own engine. The results below show how sharply file size drops as width decreases, because file size scales with the total pixel count, and pixel count falls with the square of the width.
File size by target width (measured on 24 real photos)
| Target width | Average file size | Reduction vs 4.5 MB original | Best for |
|---|---|---|---|
| 1920 px | 524 KB | -88% | Full width web banners, hero images |
| 1280 px | 249 KB | -94% | Email attachments, large content images |
| 800 px | 107 KB | -97% | In content, blog body, sidebar images |
| 640 px | 72 KB | -98% | Thumbnails, avatars, previews |
Why the file size drops so steeply
When you halve an image's width, you also halve its height (proportions are kept), so the total pixel count drops to roughly a quarter. File size for photographic content tracks pixel count closely, so going from 4284 pixels wide down to 1920 removes about 88% of the file weight in a single step. Cutting further to 800 pixels removes about 97%. This is why resizing is the most powerful first move for anyone dealing with oversized photos, because it does far more than tweaking compression quality ever could. If you also want to change the file type while you are at it, convert afterwards with tools like JPG to WebP or PNG to WebP for even smaller files.
Recommended widths by use case
Choosing the right width depends on where the image will be used. For full width hero and banner images on a website, 1920 pixels is the practical standard, since 1920 x 1080 is the most common desktop screen resolution worldwide, so a 1920 wide image covers the vast majority of displays without waste. For blog and article body images, 1200 pixels is a strong default: it suits most content columns and leaves headroom for high density (Retina) screens. For in content, sidebar, and supporting images, 800 pixels is usually plenty and keeps files light. For email, aim around 1280 pixels and a file under roughly 200 KB so the message stays deliverable. For profile photos and avatars, 400 to 640 pixels covers most platforms, which display them small. For thumbnails and previews, 150 to 300 pixels is enough.
Does resizing reduce quality?
When you make an image smaller (downscaling), the answer is essentially no, as long as a good algorithm is used. Convertify resizes through libvips, which performs the final stage of every reduction with a Lanczos3 filter, the same high quality method used in production image pipelines. At normal viewing sizes the resized image is visually indistinguishable from the original. Two honest caveats apply. First, most camera and phone photos are already JPEG compressed, so any re-save loses a tiny, generally invisible amount of detail. Second, enlarging an image beyond its original size (upscaling) cannot add detail that was never captured, so Convertify is built for making images smaller, not larger.
What Convertify resize does not do
Convertify resize keeps the whole image, so it does not crop or reposition manually. To trim edges use Crop Image. It does not upscale beyond the original size (only downscale), does not stretch or distort, and batches are limited to 10 files at a time. Your image keeps its original format by default, or convert to any of 14 formats in the same pass. Need to combine several resized images into one document? Try images to PDF.