To resize an image well, begin with the place where the file will be used. A form asking for 1200 × 800 pixels presents a different task from an email attachment that only needs to be smaller in megabytes. This page changes pixel dimensions and lets you export a new JPG, PNG or WebP file. It also reports the result so you can check what changed before you download it.
The tool is intended for people preparing a photo, screenshot, product image or graphic for an upload field, website, document or sharing workflow. It works best when you already know the required width or height and want a straightforward local conversion rather than a full image editor.
Choose the target before you resize an image
Read the destination requirement literally. “1200 px wide” describes a dimension. “Under 500 KB” describes file size. “4:5” describes shape. These values influence one another, but they are not interchangeable.
| Requirement says | Set or check | Important limitation |
|---|---|---|
| Exact width and height | Width, height and ratio lock | A different ratio can distort |
| Maximum width or height | Change one side with ratio locked | Check the calculated other side |
| Maximum KB or MB | Result size, format and quality | No exact file-size target |
How to resize an image on this page
- Choose an image. Use the file picker or drop a browser-readable image into the upload area. The original dimensions and file size appear below the preview.
- Enter the target size. Keep the chain icon locked when the image should retain its current proportions. Changing either dimension then calculates the other.
- Choose an output. Pick JPG, PNG or WebP. For JPG and WebP, adjust quality between 40% and 100%. PNG is exported with its lossless setting and therefore has no quality slider.
- Resize and inspect. Select Resize image, compare the preview and output details, then download the new file. The original is not overwritten.
Dimensions, aspect ratio and visible quality
Width and height describe the pixel grid. Aspect ratio describes its shape. A 4000 × 3000 photo and a 1200 × 900 copy both use a 4:3 ratio, so the smaller copy keeps the same composition without stretching.
Leave the ratio locked for most photos, screenshots and artwork. Only unlock it when the destination truly requires different proportions and distortion is acceptable. This tool does not crop: an unlocked 4:3 image forced into a square becomes narrower or wider rather than losing content at the edges.
Reducing dimensions removes pixels, which is usually appropriate when the original is larger than its final display. Enlarging creates more pixels but cannot recover detail that the source never contained. Check faces, text, product edges and fine patterns at the size where people will actually view the image.
Choose the output format and quality deliberately
JPG
Use JPG for photographs and other continuous-tone images when transparency is not needed. Transparent areas are filled with white on this page. Lower quality can reduce file size but may soften detail or introduce artifacts.
PNG
Use PNG when transparency, sharp interface graphics, diagrams or text edges matter. PNG can be much larger for detailed photographs, and this tool does not offer a lossy PNG quality control.
WebP
Use WebP for modern web delivery when the destination accepts it. WebP can retain transparency and provides an adjustable quality setting here, but a specific form may still require JPG or PNG.
Start JPG or WebP near 85–90% when visual quality matters, then inspect the result. This is a practical starting point, not a universal rule: photographs with texture, screenshots with small text and already compressed images respond differently.
How to read the result before downloading
The preview answers the first question: does the resized image still look correct? The details panel then shows the generated file rather than an estimate. Check these values in order:
- Dimensions and ratio: confirm the destination will accept the width, height and shape.
- Output size: compare the bytes and percentage with the original. Smaller dimensions do not guarantee a smaller file if the format also changes.
- Resolution: use the megapixel and pixel-count values to understand how much image data remains.
- Transparency and metadata: verify the background behavior. The canvas export creates a new image and does not preserve the original file metadata.
Illustrative example: prepare a large photo for a page
Suppose the input is a 4000 × 3000 JPG and the page needs an image no wider than 1200 pixels. Keep the ratio locked and enter 1200 for the width. The tool calculates 900 pixels for the height, producing a 1200 × 900 image with the same 4:3 shape.
| Output | Width scale | Resolution | Aspect ratio |
|---|---|---|---|
| 1200 × 900 | 30% | 1.08 MP | 4:3 |
Illustrative example. The final file size depends on the image content, source encoding, chosen format and quality; use the generated result panel for the actual value.
Where this focused tool fits, and where it does not
base97 is intentionally narrow here: it processes one image locally, accepts exact pixel dimensions, exports three common formats and presents an output-versus-original report. There is no account step, upload queue or multi-screen editor in this workflow.
It does not currently provide batch resizing, cropping, social-media presets, exact KB targeting, AI enlargement, manual metadata editing, SVG export or advanced codec controls. Use a tool built for those needs instead of forcing this resizer to do a different job.
- Adobe Express provides a broader design and editing workflow when resizing is only one step in preparing social or marketing artwork.
- Canva is a better fit when the resized image needs to stay inside a larger design layout or be adapted into reusable visual formats.
- iLoveIMG is a better fit when you need multiple images, percentage-based resizing or cloud-file import in one workflow.
- Squoosh exposes more codecs and detailed compression controls for users who want to tune encoding.
Troubleshooting common resize problems
The image looks stretched
The output ratio differs from the source ratio. Re-select the original, lock the chain control and change only width or height. If the destination needs a different shape, crop in a separate editor instead of stretching.
The result looks soft or blocky
Avoid enlarging a small source and raise JPG or WebP quality if compression artifacts are visible. Judge the file at its intended display size, not only while zoomed far beyond 100%.
The file is still too large
Try a smaller pixel size, choose JPG or WebP for a photograph, or lower quality gradually. This tool reports the actual output size but does not guarantee an exact KB target.
The browser cannot finish the resize
Very large dimensions can exceed available browser memory even though each side is capped at 12,000 pixels. Try smaller dimensions, close memory-heavy tabs or use a desktop editor for unusually large files.
Common questions about resizing images
Does resizing upload my image?
No. This page reads the selected image and creates the resized file with browser image and canvas APIs. The tool does not send the image to a base97 server.
Can I resize an image to an exact file size such as 200 KB?
Not with this tool. You can choose dimensions, format and JPG or WebP quality, then inspect the actual output size. It does not target an exact KB or MB value.
Does changing width and height crop the image?
No. With the aspect ratio locked, the image keeps its shape. If you unlock it and enter a different ratio, the whole image is stretched or squeezed into those dimensions rather than cropped.
Why can the resized file be larger than the original?
A larger pixel grid, a less efficient output format or a high quality setting can create a larger file. Compare the output size and dimensions shown in the result panel before downloading.
Research and editorial notes: Tool behavior was checked against the base97 implementation on September 27, 2026. Browser scaling and export behavior were reviewed against MDN documentation for drawImage() and toBlob(). Competitor comparisons use official product pages and explain scope rather than claim universal superiority.