Image Checker: validate an image against rules
Check an image against dimension, file-size, format, and aspect-ratio rules online, free. Auto-correct to comply — no upload, runs in your browser.
The resize, compress, and check tools load in your browser. Nothing is uploaded to a server — all processing happens on this device. If you are reading this, the interactive tool is still loading or JavaScript is disabled.
Many submission forms require an image to meet specific rules: a maximum or minimum file size, exact or minimum or maximum width and height, an allowed set of formats, or a particular aspect ratio within a tolerance. The Image Checker evaluates every rule you provide in a single pass and tells you whether the image passes or fails.
When an image fails, the checker lists each rule that was violated along with the value it required and the image’s actual value, and it shows the image’s real width, height, file size, format, and aspect ratio. If you ask it to, the tool can automatically correct the image by resizing, compressing, and converting format, then revalidate the complete rule set and report any rule that still cannot be satisfied.
FAQ
- Can it fix an image that fails?
- Yes. Automatic correction resizes, compresses, and converts the format to try to satisfy all of your rules, then checks the whole rule set again. If it cannot satisfy every rule it tells you which ones remain, and your original image stays available.
- Which image requirements can I check?
- You can check dimensions, file size, format, and aspect ratio. Each rule is optional, so enter only the requirements from the form or service you are preparing the image for.
- Does checking modify my image?
- No. Checking only evaluates the uploaded image. Automatic correction is a separate action, and the original image remains available.
- How do I check image dimensions and file size?
- Upload the image and enter the required width, height, or file-size rule. The checker compares those limits with the image’s measured properties.
- Can I check an image format before uploading it to a form?
- Yes. Add the allowed format rule to see whether the image matches it, and use automatic correction if you want to try converting it.
- Are my images uploaded anywhere?
- No. Images are decoded, resized, compressed, and checked inside your own browser. The image bytes, the filename, and the metadata never leave your device, which you can confirm in your browser’s network inspector.
- Is it free?
- Yes. Every tool on this site is free to use, and no account or sign-up is required.