 <p>Just remove the <code>return jsonify(ret_data)</code> line form your <code>send_recommend()</code> route. </p> <pre><code>@app.route('/send_recommend', methods=['GET', 'POST']) def send_recommend(): if request.method == 'GET': ret_data = {"data": request.args.get('data')} #do something here </code></pre> <p>Because you are returning the JSON data back to your template.</p>