G: Here’s a quick bash one-liner using exiftool to add a tag (keyword) xyz to all images in the current directory:

G: For multiple tags, you can just repeat the -Keywords+= option for each tag:

Single directory:

for img in *.jpg; do exiftool -overwrite_original -Keywords+=xyz -Keywords+=abc -Keywords+=123 "$img"; done

Recursive (all subdirectories):

find . -iname '*.jpg' -exec exiftool -overwrite_original -Keywords+=xyz -Keywords+=abc -Keywords+=123 {} \;

Key points:

• Each -Keywords+=tag appends that tag.
• -Keywords="tag1, tag2, tag3" would replace all keywords, not append.
• Tags can contain spaces if you quote them: -Keywords+='My Tag'

If you want to batch-append the same set of tags to all files at once:

G:

TL;DR:

• Yes, other common tag types include:
  • Subject
  • Title
  • Description (or ImageDescription)
  • Comment
  • TagsList
• Preserving file modification time:
  Use exiftool with -P to preserve the filesystem timestamps.

Common Tag Fields Besides Keywords

Here are useful alternatives depending on what you want: | Field | Purpose | Example exiftool flag | |------------------|------------------------------------------|----------------------------------| | Subject | Often used for topics or categories | -Subject+=xyz | | Title | Short descriptive title | -Title="My Image" | | Description | Longer image description | -Description="Some text" | | ImageDescription | EXIF-specific description | -ImageDescription="Details" | | Comment | General comment | -Comment="Note here" | | TagsList | XMP tag list (can be more standardized) | -TagsList+=xyz |

Keywords vs. Subject:
Some programs (like Lightroom) use Keywords primarily, while others (like Windows Explorer) display Subject more prominently.

Preserve File Modification Time

By default, exiftool changes the filesystem modification timestamp.
To prevent that: