Image Format Detector
Free online image format detector. Drop a file and it reads the real signature, not the extension, to reveal the true format, MIME type, and image details.
How to Detect the Real Format of an Image
Drop any images into the detector. It reads each file’s magic bytes and reports the true format, MIME type, and key details — even when the extension is wrong.
Step 1
Add Images
Drop a file or pick several at once; the detector loads them locally, nothing is uploaded.
Step 2
Read Signature
It scans each file’s magic bytes to find the format, ignoring the extension and any wrong label.
Step 3
See Details
Review the detected format, MIME type, size, and properties, or remove a file and start over.
Free Online Image Format Detector to Check and Identify Any Image Type
A file’s name can lie, but its bytes never do. Every image format begins with a fixed fingerprint called a file signature, or magic bytes — a short sequence at the very start of the file that identifies what it really is. The extension after the dot is only a label someone typed, and labels get changed: a social app silently re-encodes a download as WebP but keeps a .jpg name, a screenshot saved as a .png refuses to open in a photo app, or an iPhone photo that looks like a normal picture is actually HEIC. When a converter rejects a file or an upload fails, guessing from the extension wastes time. An image format detector solves this by reading the real signature instead of trusting the name, so you always learn the true format of the image in front of you.
Our free online image format detector runs entirely in your browser and reads the actual bytes of every file you drop in. It recognizes fourteen formats by their signatures: JPEG, PNG, GIF, BMP, WebP, TIFF, ICO, CUR, HEIC, HEIF, AVIF, SVG, JPEG XL, and JPEG 2000. For each file it does more than name the type — it parses the header to show useful details: pixel dimensions, color depth and color type, whether the image has an alpha channel or transparency, if it is animated, and whether EXIF, ICC, or XMP profiles are embedded. You can add several images at once, and the tool lists each one with its detected format, MIME type, and file size, so bulk-checking a folder is as easy as checking a single picture.
People use an image file type checker for very practical reasons. Designers and developers confirm the true format before feeding a file to a converter that keeps rejecting a mislabeled upload. Anyone who downloads images from chat apps, social media, or stock sites can verify whether a ‘jpg’ is really a WebP or a PNG. Photographers and archivists spot HEIC and TIFF files that ordinary viewers cannot open, and asset teams quickly flag every wrong extension in a batch before cataloging. The detector also raises a clear warning whenever the extension does not match the real format — for example a file named photo.png that is actually a JPEG — so you catch the mismatch before it causes a broken link or a failed import. Because it reads only the header, it never alters your picture.
Why use an online image format detector instead of desktop software or a command line? There is nothing to install and no account to open — open the page, drop a file, and read the result on any device. The tool is fully client-side: your images are analyzed in the browser and never uploaded to a server, which keeps even sensitive files private. It stays free, adds no watermark, and works as both a quick single-file identifier and a batch checker. Unlike a converter that rewrites the file or a metadata editor that changes tags, this detector only tells you what the image is, leaving each byte exactly as it found it. Drop a file above to identify its true image file type in seconds.
Reads Magic Bytes
Identifies the true format from the file signature, not the extension, so a fake label cannot fool it.
14 Formats
Recognizes JPEG, PNG, GIF, BMP, WebP, TIFF, HEIC, HEIF, AVIF, SVG, ICO, CUR, JPEG XL, and JPEG 2000.
Batch Check
Drop several images at once and see each file's real format, MIME type, and size in one list.
Wrong-Extension Alert
Warns you when the name says one format but the bytes reveal another, so mislabeled files are caught early.
Deep Properties
Shows dimensions, bit depth, color type, alpha, animation, and embedded EXIF, ICC, or XMP for each file.
Private & Local
Your images are read in the browser and never uploaded, so detection stays free, fast, and fully private.
FAQ
Frequently Asked Questions
An image format detector reads the file signature, or magic bytes, at the start of a file to tell you the real format. Unlike the extension, which can be renamed, the bytes are fixed, so the tool reports the true type even when the name is wrong.
Drop the file into this free tool and it reads the actual bytes in your browser, then shows the detected format, MIME type, and size. No upload happens, so you can identify the image type on any device in seconds.
Our detector recognizes fourteen formats by signature: JPEG, PNG, GIF, BMP, WebP, TIFF, ICO, CUR, HEIC, HEIF, AVIF, SVG, JPEG XL, and JPEG 2000. If a file uses an unknown signature, the tool reports it as unrecognized rather than guessing.
Extensions get changed by hand, lost during transfer, or rewritten by apps that re-encode a download. A chat app may save a WebP with a .jpg name, or a screenshot may be a PNG. The detector reads the bytes, so it always reports the real format.
Yes. The tool compares the detected format with the file’s extension and shows a clear warning whenever they do not match — for example a photo.png that is actually a JPEG. This helps you catch mislabeled files before a failed upload or broken link.
Yes. Beyond the format name and MIME type, it parses the header to show dimensions, bit depth, color type, alpha or transparency, animation status, and whether EXIF, ICC, or XMP profiles are embedded in the file.
Yes. The detector runs entirely in your browser and reads only the file header, so your images are never uploaded to a server. Nothing is sent anywhere, no account is created, and even sensitive files stay private on your device.
Yes. You can select or drop several files together, and the tool detects each one and lists its format, MIME type, and size in a single view. This makes batch-checking a folder for mislabeled or unknown formats quick and easy.
No. The detector only reads the file header to identify the format; it does not convert, re-encode, or modify your image in any way. Each byte stays exactly as it was, so you get the answer without altering the original picture.
Yes. This free image format detector works in your browser with no sign-up, no watermark, and nothing to install. Check as many files as you like to identify their true format, and keep your images private the whole time.