Is PNG image checker
Find out whether a file is truly a PNG, whatever its extension claims. Everything is checked on your device.
- Your files are never uploaded
- Processed on your device
- Works offline
- Free, no sign-up
Drop your images here
Images · up to 10 files, 100 MB each
or paste with Ctrl+VLive preview
Settings
No settings needed. Add your files and convert.
Nothing is uploadedHow it works
Add your images
Choose one or more image files to check for the PNG format.
Read the verdict
See the detected format and a clear Yes or No answer for each file.
Act on the result
Convert or rename with confidence, knowing the true format of every file.
Extensions lie, signatures do not
File extensions can be renamed in seconds, so a file called photo.png may actually be a JPEG, a WebP or something else entirely. This tool ignores the name and reads the first bytes of each file, the magic signature that reveals what the image truly is inside.
Knowing the true format matters before you upload to a site with strict rules, embed images in a document, or debug why a picture will not open in an app.
Private by design: checked on your device
Every check happens inside your own browser using only the first few bytes of the file. Your images are opened and inspected locally, and nothing is transmitted anywhere, so even sensitive or unreleased artwork stays completely in your hands.
There is no account, no queue and no waiting room: open the checker whenever you need it, drop files in, read the answers and close the tab. Your browser only keeps the app itself for offline use, never your pictures.
When to check for PNG and what to do next
Use this check when a download refuses to open, a marketplace demands PNG uploads, or you suspect a renamed file is breaking your project. The report names the detected format for every file, so you can spot JPEGs, WebPs and GIFs hiding under a .png extension at a glance.
If a file turns out not to be a PNG, convert it properly instead of just renaming it: our image converter rewrites the actual data. For a full breakdown of size, dimensions and colours, try Analyze image next.
Questions
Are my files uploaded?
No. The signature check runs inside your browser on your own device. Your files are never sent to us or to anyone else.
Is it free?
Yes. Free to use, with no sign-up, no watermark and no daily limits.
Why does the detected format differ from the extension?
Extensions are just part of the file name and can be renamed freely. The detected format comes from the file's magic bytes, which describe its real contents.
What if the format shows as unknown?
The file is likely damaged, truncated, or in a format browsers cannot recognise. Try opening it in its original app and exporting it again as PNG, JPG or WebP.
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