When buying a hiking baby carrier there are several factors you need to take into account. Cost. How much you'll want to invest in a carrier backpack depends on 1)your budget 2) how long your hikes will be 3) how often you will go hiking. If you're only going to do easy short hikes a few times a year you don't need to invest in as a good a carrier as if you're going more frequently or doing longer hikes.  Metal Frame or Soft Carrier. A metal frame will add more weight, making it less comfortable for you, but more comfortable for your child. These are suitable when hiking with toddlers or when you're planning a longer hike. A soft carrier is lighter making it more comfortable for you. It's best suited for babies up to 36 months weighing no more than 25 lbs. But you may find that it's not comfortable for them once they start getting close to that limit.  Adjustable Straps. This is a must as it means that your child carrier backpack will have longer longevity and be more versatile if more than one person will be carrying it. Look for adjustable torso straps, adjustable hip straps, adjustable shoulder straps and adjustable foot stirrups so that you can continue using your carrier as your child grows.  Storage Capacity. You'll also want to consider the size and storage space of the backpack you purchase. How much storage capacity you need will depend on how long your hikes are and how much stuff you bring.  Additional Features. Consider whether you'll use the 'extras' you are paying for. Not only are they more expensive, but they also add extra weight.  Some child backpack carriers come with spaces for canopies, built-in sunshades, add-on packs, detachable pouches and lots of storage. All of these features increase the weight of your backpack so carefully consider which ones you'll actually use.  Customer Reviews. A further thing to look at is reviews of the carrier you intend to buy. This provides valuable insight into its worthiness as a purchase from other parents who were looking for the same thing as you.