Best free image enhancer AI tool for improving image quality?

 AirBrush, a very popular and powerful free AI image enhancer app for smartphones (available on iOS and Android). It's designed primarily for selfies and portrait photography but has expanded to include general photo editing features.

If you are looking for a mobile app to quickly enhance selfies, remove blemishes, whiten teeth, and apply filters, then AirBrush is exactly what you're asking about.

How to Use AirBrush for Basic Image Enhancement:

1. Download and Install: Get the AirBrush app from the Apple App Store or Google Play Store. It has a free version with limited tools and a paid subscription for full access.

2. Open Your Photo: Launch the app and select a photo from your gallery or take a new one.

3. Use the Editing Tools: The tools are typically listed as icons along the bottom or side.

4. Beauty: This is the main tab. Tap on features like "Smooth," "Reshape," or "Blemish Remover" and adjust the intensity with a slider.

Filters: Browse categories of filters and tap to apply. You can usually adjust the filter's strength.

Tools: Access more advanced adjustments like "Crop," "Brightness," "Blur," and "Body Tuner."

5. Save Your Work: Once you're happy, tap the save/download icon. The app will save the enhanced image to your camera roll.

Limitation: While AirBrush is excellent for quick photo enahancements, its upscaling capabilities (increasing image resolution significantly) are very limited or non-existent. For true, high-quality upscaling, you need different tools.