How to open .SI files on Windows
To open .SI files on Windows, open the .SI file with a text editor (e.g., Notepad) to view the XML contents and the embedded URL/message.
Step-by-step instructions
- Open the .SI file with a text editor (e.g., Notepad) to view the XML contents and the embedded URL/message.
- If the content is binary/gibberish, confirm whether it is actually compiled SI (SIC) content; handle it with WAP/WBXML tooling rather than a text editor.
- For server/workflow use, verify the correct Content-Type when serving: text/vnd.wap.si for SI (and application/vnd.wap.sic for compiled SI).
Common issues
The .SI file opens as unreadable symbols or binary data
Service Indication can also be carried in a compiled/binary form (commonly associated with the SIC media type) rather than the plain text/XML form expected for SI.
- Open the file in a hex viewer or text editor to confirm whether it is plain XML text or binary data.
- If it is binary, treat it as compiled SI content (application/vnd.wap.sic) and decode it with WAP/WBXML tooling rather than editing it as text.
- Ask the sender/system whether the payload is intended to be SI (text) or SIC (compiled) and request the appropriate form.
Browser or server delivers the wrong content type
WAP-related workflows rely on correct MIME types; an incorrect Content-Type can prevent gateways/clients from recognizing the payload.
- Configure the web server to serve SI documents with Content-Type: text/vnd.wap.si.
- If you are actually serving compiled SI, use application/vnd.wap.sic for that payload.
- Re-test the endpoint and verify headers with a network inspector or command-line HTTP client.
The file is rejected by a legacy WAP/Push gateway
Gateways may require SI documents to conform closely to the SI specification (structure and required fields).
- Validate the SI XML structure against the Service Indication specification.
- Confirm timestamps/attributes and required elements are present as expected by the target gateway/device profile.
- If a compiled form is required by the gateway, generate/obtain the correct compiled SI (SIC) payload instead of sending text SI.
Security note
.SI (WAP Push SI) documents commonly contain URLs meant to prompt user action; treat unexpected SI files as potentially phishing-related and verify links before opening them.