Check If an Image Is a PNG
Read a file's real bytes to confirm whether it is a true PNG. Runs entirely in your browser, so your data never leaves your device.
Drop a file here, or click to browse
Files never leave your device
Output
The result appears here as you type.
How to use Check If an Image Is a PNG
- 1. Upload the file in question. Drop in the file to verify, even one that already carries a .png extension. The tool inspects the actual bytes rather than trusting the name on disk.
- 2. See the signature check. The tool checks for the eight-byte PNG signature, including its fixed leading bytes, that every genuine PNG file must start with before any image data follows.
- 3. Read the verdict. Note the yes-or-no result, which names the actual format detected when the check fails, such as a JPEG saved under a .png name by an image editor.
When to use Check If an Image Is a PNG
Check If an Image Is a PNG reads a file's real header bytes to confirm it is truly a PNG rather than a renamed or misconverted file. Use it whenever a workflow depends on a file genuinely being PNG data, not just having the right extension.
- Guarding a logo upload field. A branding tool requires PNG logos so it can preserve transparency, but users sometimes upload a JPEG saved with a .png extension. Checking the signature catches this before transparency silently breaks.
- Auditing exported assets. A design tool exported a batch of icons, and some appear to have failed silently. Checking each file's real signature identifies which ones are actual PNGs and which are empty or wrong.
- Verifying a screenshot tool's output. A screenshot utility claims to save PNG files, but one file behaves oddly in an image pipeline. Checking its bytes confirms whether it is genuinely a PNG or was written in another format.
Examples
Renamed file
Input
logo.png (actually a JPEG)
Output
No — it looks like a JPEG file.
About the Check If an Image Is a PNG tool
Check If an Image Is a PNG runs as plain JavaScript in your browser tab, with no server behind it. Read a file's real bytes to confirm whether it is a true PNG. Whatever you put in stays on your device from start to finish.
The tool is part of EditSafely's Image Tools section, 200 single-purpose utilities built around the same idea: open the page, get the result, keep your data to yourself.
There is nothing to configure. Provide the input and the result appears on its own. A worked example further down the page shows exactly what the tool produces for a real input.
That local-first design has practical benefits beyond privacy. The tool keeps working on a flaky connection once the page has loaded, results are instant because nothing round-trips to a server, and it is safe to use with confidential material.
Frequently asked questions
Does Check If an Image Is a PNG cost anything?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Are my files uploaded to a server?
No data leaves your device. The whole tool is JavaScript that runs inside your browser tab, so there is no upload, no server-side processing and no log of what you did. If you disconnect from the internet after the page loads, it keeps working.
Which files does Check If an Image Is a PNG accept?
It accepts images in any common format (PNG, JPG, WebP, GIF and more). There is no file size cap imposed by a server; very large files are limited only by your device's memory.
Do I need to sign up or install anything?
Nothing to install and no account needed. Open the page in any up-to-date browser, including on a phone or tablet, and the tool is ready.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.