Epistolaire is an Android app to backup SMSes AND MMSes (unlike most "SMS backup" apps), in a nutshell.
- saves SMS/MMSes to a JSON file that's very close to a dump of Android's message database
- also saves images etc. from MMSes
- includes a JSON to pretty-HTML converter
- free and open-source, no ads
- cannot restore messages from the JSON file to Android SMS/MMSes
- UI is ugly because it's my first Android app
- the output file is a JSON object having a "conversations" key (value is a JSON array)
- a conversation is a list of messages (JSON objects)
- a message is either a SMS or an MMS
- a SMS has all the keys a SMS message has in the content://sms/ context
- examples: _id, thread_id, address, date, date_sent, type, body
- a MMS has all the keys a MMS message has in the content://mms/ context plus extra keys
- examples: _id, thread_id, date, msg_box
- extra MMS keys are "addresses" (a list of strings being the sender then the recipients) and "parts"
- each MMS part is a JSON object having all the keys a part has in the content://mms/part/ context
- examples: _id, mid, text, ct, name
- MMS parts having a binary file have the content encoded as base64 in the "my_content" key
See backup.schema.json file for a JSON-schema description.
The JSON to HTML converter is a separate Python script in the "viewer" directory. It will create an HTML file per conversation.
cd viewer
./converter.py path/to/backup.json
If your JSON file is very big, Python might not be able to load the whole file in RAM and thus crash.
Installing ijson (with sudo apt install python3-ijson or pip install ijson) will make the converter
able to process the JSON data without loading everything in memory at once.
Epistolaire doesn't upload your messages anywhere. It just dumps a JSON file on your device. Make sure any third-party app doesn't harvest your device's files though.
I don't use google-play, and I don't intend to ever do, so I won't upload Epistolaire on it.
Epistolaire is licensed under the Unlicense, which is basically public domain.