Steganography is the practice of hiding information in the code that makes up digital files and preventing unwanted people from knowing the existence of hidden information. High-capacity steganography techniques have been successfully performed using LSB with binary addition method, but the quality can be improved using LSB with modified binary addition. By using binary addition, message insertion can be done with two bits at once in one insertion process. For six examples of images, the message insertion process is carried out using the binary addition method and modified binary addition method with the use of 100% capacity or using all pixel values of the image. Then the SSIM, MSE, and PSNR values are calculated from each test result. This study shows that the modified binary addition method has better quality than the binary addition method. The test results show that the binary addition method produces average SSIM, MSE, and PSNR values respectively 0.971743, 9.711678, and 38.26588. Meanwhile, modified binary addition resulted in the values of 0.993287, 2.112745, and 44.88844. These results indicate that the modified binary addition method produces better quality than binary addition while maintaining high message capacity.