---
title: "Media optimization"
url: "https://audioguidekit.org/docs/content/optimization"
description: "Optimize audio and images for the best quality and file size"
lang: "en"
updated: "2026-09-19T16:42:38.209Z"
---

# Media optimization

[Docs](https://audioguidekit.org/docs) / Content / Media optimization

# Media optimization

Optimize audio and images for the best quality and file size

Optimizing your media files reduces download times and improves the visitor experience, especially for offline use.

## Audio optimization

### Recommended settings

| Setting | Recommended | Why |
| --- | --- | --- |
| Format | M4A (AAC) or MP3 | Universal browser support |
| Bitrate | 128 kbps | Perfect for speech |
| Sample rate | 44.1 kHz | Standard quality |
| Channels | Mono | Speech doesn't need stereo |

### Why these settings?

-   **128 kbps** is ideal for speech—higher bitrates don't improve voice quality
-   **Mono** saves 50% file size with no perceptible difference for narration
-   **M4A (AAC)** provides better compression than MP3 at the same quality

### Using FFmpeg

[FFmpeg](https://ffmpeg.org/) is a free tool for audio conversion.

**Convert a single file:**

```
ffmpeg -i input.wav -c:a aac -b:a 128k -ac 1 output.m4a
```

**Batch convert all WAV files:**

```
for f in *.wav; do
  ffmpeg -i "$f" -c:a aac -b:a 128k -ac 1 "${f%.wav}.m4a"
done
```

**Convert MP3 to optimized M4A:**

```
ffmpeg -i input.mp3 -c:a aac -b:a 128k -ac 1 output.m4a
```

### File size estimates

| Duration | 128 kbps Mono | 256 kbps Stereo |
| --- | --- | --- |
| 1 minute | ~1 MB | ~2 MB |
| 5 minutes | ~5 MB | ~10 MB |
| 30 minutes | ~30 MB | ~60 MB |

A typical audio guide with 10 stops averaging 3 minutes each will be around 30 MB total—manageable for offline download.

## Image optimization

### Recommended settings

| Setting | Recommended |
| --- | --- |
| Format | WebP or JPEG |
| Width | 800-1200px |
| Quality | 80% |
| Color profile | sRGB |

### Why these settings?

-   **WebP** offers 25-35% smaller files than JPEG at the same quality
-   **800-1200px** width is sufficient for mobile screens
-   **80% quality** balances file size and visual quality
-   **sRGB** ensures consistent colors across devices

### Using ImageMagick

[ImageMagick](https://imagemagick.org/) is a free tool for image conversion.

**Convert to optimized JPEG:**

```
convert input.png -resize 1000x -quality 80 -strip output.jpg
```

**Convert to WebP:**

```
convert input.png -resize 1000x -quality 80 output.webp
```

**Batch convert all PNG files:**

```
for f in *.png; do
  convert "$f" -resize 1000x -quality 80 "${f%.png}.webp"
done
```

### Using Squoosh

[Squoosh](https://squoosh.app/) is a free browser-based tool from Google for image optimization. Drag and drop images to compress them without installing anything.

### File size targets

| Image Type | Target Size |
| --- | --- |
| Stop image | 50-150 KB |
| Cover image | 100-200 KB |
| Thumbnail | 20-50 KB |

Avoid images over 500 KB. Large images slow down loading and consume visitor data, especially on mobile networks.

## Bulk optimization workflow

For tours with many files, consider this workflow:

1.  **Organize source files** in a folder structure
2.  **Run batch conversion** scripts for audio and images
3.  **Upload optimized files** to your hosting provider
4.  **Verify quality** by testing a few files in the browser

### Example folder structure

```
tours/
├── audio/
│   ├── 01-welcome.m4a
│   └── 02-history.m4a
└── images/
    ├── cover.webp
    └── stop-01.webp
```