Définition
File signature
A file signature is a recognizable byte pattern near the start of a file.
Why file signatures matter
Extensions can be changed easily, but the opening bytes of a file often still reveal what format it really belongs to.
That makes file signatures useful for validation, troubleshooting, and format detection.
When signature checks help
Signature checks are especially useful when a file has the wrong extension, fails to upload, or behaves differently from what its name suggests.
They are also a practical first step when you need to identify an unknown file before opening it in a more specialized tool.
Outils associés
More tools that cover similar file tasks.
Ouvrir l’outil
Vérificateur de signature de fichier
Continue with a focused tool for the next part of the job.
Ouvrir l’outil
Vérificateur de type MIME
Continue with a focused tool for the next part of the job.
Check metadata
Voir les métadonnées
Open the full metadata view and inspect the file in more detail.