When an interviewer asks you why you are looking for a new job, you want to respond honestly and tactfully. Focus on the positive reasons for wanting to make a change, such as seeking growth opportunities or a better work-life balance, rather than solely on the negative aspects of your current job. It's also important to avoid speaking badly about your current employer or colleagues, as this can reflect poorly on your professionalism and attitude. Remember to keep your response concise and relevant to the position you are interviewing for, showcasing how your career goals align with the company's mission and values.