Change Size of Image
Change the size of an image in a few clicks, and get the same kind of file back. Upload a JPG, PNG or WebP picture, set the new size as a percent, a longest side, or a width and height in pixels, and download the result. By default the tool keeps the format of your picture, so a photo stays a JPG and a transparent PNG stays a PNG. It handles one picture at a time and only makes a picture smaller.
- The tool only makes a picture smaller. A picture already smaller than the size you ask for keeps its size, and the result panel says it was not resized.
- Changing the pixel size recalculates the pixels, so fine details can soften. Results vary with the picture.
- Free web use is limited to 5 MB per image and 30 images per day per visitor.
Drop an image here
PNG, JPG, WebP, AVIF, GIF, BMP or TIFF, up to 5 MB
The picture is only ever made smaller, never larger: one already below this size keeps its size. The credit cost is the same as a plain conversion.
Lower means a smaller file and more visible loss (1 to 100).
Complete the human check to enable the button.
Result
Your image will appear here.
The free web tool takes images up to 5 MB, 30 per day. Signed in, the limit is 10 MB. The image keeps its pixel size unless you choose Make smaller.
Retention: web-tool results are deleted after 10 minutes. API results are kept 1 day on the free plan and 7 days on Starter and Pro (30 days on Business and Scale). A record of each job (type, time, status and credits, not what you submitted) is kept for 30 days without an account, or while your account exists if you are signed in.
No account needed
30 images per day for free, no watermark.
Original size by default
The image is re-encoded at its full pixel size unless you choose Make smaller. Camera and location tags are not copied into the result.
Deleted automatically
Web tool results are removed after 10 minutes.
Privacy: what you submit is used only to make this file. It is deleted when the job ends, also from the job record, and the result is deleted after 10 minutes. See the privacy policy.
Do this from your code
The same conversion as an API request: send the image bytes, then poll the job. It needs an API key; a free account can create one.
curl -X POST "https://api.aiipworld.com/v1/image-jobs?op=image_resize&width=800" \
-H "Authorization: Bearer $AIIPWORLD_API_KEY" \
-H "Content-Type: image/png" \
--data-binary @input.png
# returns {"job_id": "...", "status": "queued", "credits_reserved": 1}; then poll:
curl https://api.aiipworld.com/v1/jobs/JOB_ID -H "Authorization: Bearer $AIIPWORLD_API_KEY"Batches
The web tool handles 1 image at a time. The API takes one request per image, so you can script as many as your plan allows.
Retention
Web-tool results are kept 10 minutes; free API results 1 day; Starter and Pro results 7 days; Business and Scale 30 days. The web tool allows 10 conversions per minute and 50 per day per visitor.
In one sentence
A free online tool that makes a JPG, PNG or WebP picture smaller in pixels by percent, longest side, or width and height, and by default returns the same format; it never makes a picture larger.
Key facts
- Input: a PNG, JPG, WebP, AVIF, GIF, BMP or TIFF up to 5 MB in the free tool and 10 MB when signed in, and up to 16 MP (4096 x 4096); the type is read from the file content.
- Settings: size by percent (1 to 100), longest side or width and height (1 to 16384 px, proportions kept, fits inside the box); save as the same format as the original (default), PNG, WebP, JPEG or GIF; quality 1 to 100 for JPG and WebP (default 80); a picture already smaller than the size asked for keeps its size.
- In our test a generated 2400 x 1600 px JPG of 437 KB became a 1200 x 800 px JPG of 60 KB at width 1200, a generated PNG kept its PNG format and a generated WebP stayed a WebP; the test pictures were generated by our scripts and results vary.
- It changes pixel dimensions only; it does not set the DPI value of the file.
- Free without an account: up to 10 conversions per minute and 50 per day per visitor, no watermark. Signed in, each render costs 1 credit (100 free credits every month).
- Files are deleted automatically: 10 minutes after conversion without an account, 1 day with a free account.
- Developers can run the same job with POST https://api.aiipworld.com/v1/image-jobs?op=image_resize (the image as the request body, settings in the query string) and an API key (see the API docs page).
Sources
Last reviewed:
How it works
- Upload one picture. The tool shows a preview and the image size before you start.
- Under "How to set the size", choose percent of the original, longest side in pixels, or width and/or height. The default is 50 percent.
- Leave "Save as" on "Same as the original" to get the same format back, or pick PNG, WebP, JPEG or GIF to change it.
- For a JPG or WebP picture, move the quality slider if you want a smaller or a sharper file. The default is 80.
- Click "Change size" and download the result. Download links are short-lived, so save the file soon after it is ready.
Example output
Original JPG, 2400 x 1600 px, 437 KB
Resized JPG, 1200 x 800 px, 60 KB
How to change size of image files online
Changing the size of an image takes one upload and one setting. Start with the percent option if you want the same picture at a smaller scale. Start with width or height if the picture must fit a certain space on a page, in an email or in an app.
The tool handles one picture at a time. Each job is checked for type, size and pixel count before upload, so you see a problem early. When the job ends, the result panel shows the new pixel size and file size.
The format stays the same
Unlike a tool built for one format, this page starts with "Save as" on "Same as the original". A JPG comes back as a JPG, a PNG as a PNG and a WebP as a WebP. A GIF comes back as a GIF, and an animated GIF or WebP keeps all its frames. Other types change - BMP and TIFF files come back as PNG, and AVIF files as WebP.
If you want a different format, open the "Save as" list and choose PNG, WebP, JPEG or GIF. The size setting works the same way.
If you only work with PNG files, the Resize PNG tool does the same job with PNG already chosen.
Set the size by percent, longest side or width and height
You can set the new size in three ways. Percent of the original accepts values from 1 to 100. Longest side sets the length of the longer edge in pixels, from 1 to 16384.
Width and/or height also go from 1 to 16384 pixels. An empty box means automatic, so the other side follows the proportions of the picture. In our tests, a 2400 x 1600 px JPG at height 600 gave 900 x 600 px, and the width followed on its own.
- Percent: 50 percent of a 2400 x 1600 px JPG gave 1200 x 800 px.
- Longest side: 1000 gave 1000 x 667 px.
- Height: 600 gave 900 x 600 px.
Pixel size and file size are not the same
People who search for how to change the size of an image sometimes mean the number of pixels and sometimes the size of the file in kilobytes. This tool changes the pixels. A smaller picture in pixels is usually a smaller file too. In our test, a 2400 x 1600 px JPG of 437 KB became 60 KB at 1200 x 800 px, and 39 KB at 1000 x 667 px.
To make the file smaller without changing the pixel size, use the Compress JPG or Compress PNG tool.
Quality for JPG and WebP results
A quality slider from 1 to 100 appears when the result is a JPG or a WebP, and while "Same as the original" is selected, where it applies to JPG and WebP pictures. The default is 80. A lower number gives a smaller file and a softer picture. In our test, the same 1200 x 800 px JPG was 60 KB at the default quality and 21 KB at quality 50.
PNG is lossless, so it has no quality slider. A PNG result keeps every pixel it has after resizing.
The tool never makes a picture bigger
This tool only reduces pixel size. It will not enlarge a picture, even if you type a larger width. In our test, a 2400 x 1600 px JPG with width 4000 came back at 2400 x 1600 px, and the result panel said it was not resized.
If you need a larger picture, this tool cannot do it. Use a different editor for enlargement.
Transparency and photos stored rotated
"Keep transparency" is on by default, so a transparent PNG or WebP stays transparent. A JPG has no transparency, so transparent areas are filled with a background colour, white unless you choose another.
Some photos store their orientation in a tag rather than in the pixels. The tool turns these pictures upright before changing the size. This applies to still pictures, not to animations.
Resize photo resolution online
If you want to resize photo resolution online, set the width or the longest side in pixels. The tool changes the pixel dimensions of the picture. It does not set the dots per inch (DPI) value of the file.
Limits: file size and pixels
Each image can be up to 5 MB in the free web tool. Signed-in users can upload up to 10 MB per image. Each picture can be up to 16 MP (4096 x 4096).
The tool accepts PNG, JPG, WebP, AVIF, GIF, BMP and TIFF. It does not accept SVG, PDF, HEIC or camera RAW files. Files are checked by their content, not by their name. A file that is not an image is refused with an "unsupported image" message.
- Results larger than 20 MB fail with an "output too large" message.
- A picture over the pixel limit is refused before it is decoded.
Change image size from code
You can change the size of an image with the API. Send a POST request to https://api.aiipworld.com/v1/image-jobs?op=image_resize. The body is the raw image bytes, not JSON or multipart. Set Content-Type to the type of the picture, such as image/jpeg.
Add your settings to the query string. Use format=same to keep the format of the picture. Use exactly one of scale, max_side, or width and/or height. Authenticate with Authorization: Bearer <API key> or with x-api-key.
The API returns 202 with a job_id. Poll GET /v1/jobs/:id until the job succeeds, fails or times out. This page shows a ready cURL, Node and Python example based on the settings you choose. The API takes one request per image, and there is no batch endpoint.
Possible errors are 400 invalid_params, 400 or 422 unsupported_image, 413 file_too_large, 402 insufficient_credits and 429 rate limited.
Privacy: what happens to your file
Your picture is sent to our server, where its size is changed. The uploaded image is used only to make the result. It is deleted as soon as the job ends, whether it succeeds or fails.
The result is deleted after 10 minutes in the free web tool. A record of each job is kept, and signed-in users can see their jobs in the dashboard. Camera and location tags are not copied into the result. You must have the right to use the picture you upload, as set out in our Acceptable Use Policy.
Questions
How do I change the size of an image?
Upload the picture, choose percent, longest side or width and height under "How to set the size", and click "Change size". The result keeps the format of your picture unless you pick another.
Can I change the size of an image for free?
Yes, you can change the size of an image for free in the web tool. Free use is limited to 5 MB per image and 30 images per day per visitor.
Does a JPG stay a JPG?
Yes. With "Same as the original" selected, a JPG comes back as a JPG, a PNG as a PNG and a WebP as a WebP. BMP and TIFF files come back as PNG, and AVIF files as WebP.
How do I change an image to a specific width?
Choose width in "How to set the size" and type the width in pixels. Leave the height box empty so the height follows the proportions of the picture.
Can I make an image bigger?
No, this tool only makes a picture smaller. If you enter a larger size, the result keeps its original size and the panel says it was not resized.
Does changing the size lower the quality?
Changing the pixel size recalculates the pixels, so fine details can soften. For a JPG or WebP result you can also set the quality slider. Results vary with the picture.
How do I make the file size smaller in KB?
A smaller picture in pixels is usually a smaller file. To reduce the file size without changing the pixels, use the Compress JPG or Compress PNG tool.
Does it change the DPI of the image?
No. The tool changes the width and height in pixels. It does not set the DPI value stored in the file.
What is the difference between this tool and Resize PNG?
Both use the same resizer. Resize PNG opens with PNG chosen for PNG files, while this page opens with "Same as the original" so a JPG, PNG or WebP keeps its format.
Can I change the size of several images at once?
No, the tool handles one picture at a time. The API also takes one request per image and has no batch endpoint.
Can I change the size of an image in my own code?
Yes, the API accepts a raw image body with the image_resize operation. Use format=same to keep the format, and see the Change image size from code section for the endpoint and error codes.
Need this in your app or in bulk?
This tool runs on the same platform as the API, so the same image is one HTTP request from your code. A free account includes 100 credits a month.