Use the original uncompressed source (download again, request the original file, or export from the source app)
Recreate the image from the original data (e.g., re-render from a project file, regenerate from a vector source)
If you have a slightly blurred image, try deblurring tools (e.g., Photoshop “Shake Reduction,” Topaz Photo AI/Sharpen, online deblur apps)
Use image upscaling with sharpening (e.g., Topaz Photo AI, ESRGAN-based upscalers, Photoshop Super Resolution)
Apply mild deconvolution/deblur settings in dedicated software (e.g., Richardson–Lucy style tools in deconvolution apps)
Correct camera shake before deblurring (stabilize/align, then sharpen)
Reduce noise artifacts before sharpening (denoise first, then apply deblur/sharpen)
Use edge-preserving sharpening (e.g., unsharp mask, high-pass filter) when blur is mild
If the blur is due to intentional anonymization (face/license blurring), use the original authorized source instead of trying to reverse it
Export at the highest available resolution and avoid re-compression; use lossless formats when possible (PNG/TIFF)
For motion blur, experiment with direction/strength settings in deblurring tools
For out-of-focus blur, use tools optimized for defocus deblurring and tune blur radius/PSF parameters
If results are unacceptable, replace with a clearer capture or higher-quality version