How do I compare two documents in Zoho Writer? Any sample codes?
To compare two versions of a document, you need to make use of Zoho Writer's Comparison API.
HTML Sample Code:

Upload Document1: <input type="file" name="document1" size="38"><br>
Upload Document2: <input type="file" name="document2" size="38"><br><br>
<input type="hidden" name="apikey" value="423s*****">
<input type="submit" name="submit" value="Compare Document">
</form>
Curl Sample Code:

curl --request POST \
--header 'content-type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW' \
--form document1=@/Users/username/Documents/Sample_V1.docx \
--form document2=@/Users/username/Documents/Sample_V2.docx \
--form 'apikey=423s*****'

You can also build and test Compare Document API requests right from your browser with Office Integrator Postman Collection.