RollmendMerge Google Takeout JSON metadata back into your photos
Every photo in a Google Photos Takeout comes with a JSON file. Merging means reading that JSON and writing its information into the photo itself, so any app can see it.
What is in the JSON file
| JSON field | What Rollmend writes |
|---|---|
| photoTakenTime.timestamp | EXIF DateTimeOriginal + OffsetTimeOriginal (photos), mvhd/tkhd/mdhd creation time (MP4/MOV), zip file time |
| geoData (latitude/longitude/altitude) | EXIF GPS (photos), ©xyz location (videos) – only if the file has no location yet; 0,0 means “no location” and is ignored |
| description | EXIF ImageDescription (plain text) or XMP dc:description (any language), when the file has none |
| title | Used to match the JSON with the right photo and to restore cut-off file names |
Matching is the hard part
The JSON is not always called photo.jpg.json. Rollmend handles:
photo.jpg.supplemental-metadata.json(newer exports), and the same name cut short likephoto.jpg.supplem.json- names cut at 46/47/51 characters, even inside the extension (
…camera.jp.json) - duplicates:
photo(1).jpg↔photo.jpg(1).jsonorphoto(1).jpg.json - “-edited” copies (and localized ones like “-bearbeitet”, “-modifié”), which use the original’s JSON
- old exports with
photo.jsonand JSON names where Google replaced special characters (matched through the title field)
Steps
- Open Rollmend and choose the Takeout folder or zip files.
- Check “How sidecars were matched” in the report.
- Click Fix and export.
If you prefer the command line
exiftool can do this with the right arguments, and open-source projects exist for it. They are great if you are comfortable with a terminal. Rollmend is for people who want the same result with a few clicks and a report they can check.
Questions and answers
Does Rollmend keep the existing EXIF data?
Yes. If only the date has to change, it is patched in place. When tags must be added, Rollmend rebuilds the EXIF block with the existing tags included. Keep your original export in case a camera’s maker notes don’t survive the rebuild.
Are the JSON files included in the output?
No – their information is now inside the photos. The CSV report lists which JSON was used for each file.
Last updated: 2026-10-26