Tool to extract / read the stored thumbnail of an image. EXIF format (Exchangeable image file format) allows the storage of a thumbnail image inside another image.
EXIF Thumbnail - dCode
Tag(s) : Image Processing
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EXIF Thumbnail
EXIF Thumnnail Extractor
Answers to Questions (FAQ)
What is EXIF Thumbnail metadata? (Definition)
EXIF Thumbnail metadata is information embedded in image files, usually in JPEG format, that contains a thumbnail version of the image. It is stored in EXIF (Exchangeable image file format) data and allows you to quickly preview the image without needing to load the entire file.
Not all images necessarily contain an EXIF thumbnail. This depends on how the image was created and whether the software or camera that generated the image includes this feature.
How to read EXIF Thumnnail data?
Indicate the image file to upload (JPG, PNG or other EXIF compatible format) and dCode reader will automatically extract the EXIF data and especially the Thumbnail field containing the miniature image if it exists, otherwise, it will not return any results.
Example: The following image has been modified to incorporate a thumbnail containing a secret message: 
Extracting the data may return an unreadable image file.
Why extracting EXIF Thumnnail data?
Indicate the image file to upload (JPG, PNG or other EXIF compatible format) and dCode will automatically read the EXIF data and especially the Thumbnail field containing the thumbnail if it exists, otherwise, it will not return any results.
Sometimes the thumbnail can reveal information, it happened that some images were blurred or censored but their thumbnail was not updated, so it is possible to guess the original content.
Where is EXIF Thumbnail data stored?
The thumbnail data is saved in the IFD1 in the same way as the image, itself present in APP1.
An IFD, or Image File Directory, is a data structure used in image file format.
The APP1, or Application Marker 1, is a specific section in the JPEG file format used to store data in the image file.
NB: Thumbnails have no size limit.
Source code
dCode retains ownership of the "EXIF Thumbnail" source code. Except explicit open source licence (indicated Creative Commons / free), the "EXIF Thumbnail" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, breaker, translator), or the "EXIF Thumbnail" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and all data download, script, or API access for "EXIF Thumbnail" are not public, same for offline use on PC, mobile, tablet, iPhone or Android app!
Reminder : dCode is free to use.
Cite dCode
The copy-paste of the page "EXIF Thumbnail" or any of its results, is allowed (even for commercial purposes) as long as you credit dCode!
Exporting results as a .csv or .txt file is free by clicking on the export icon
Cite as source (bibliography):
EXIF Thumbnail on dCode.fr [online website], retrieved on 2024-07-27,
