All Didymos carriers are made from the same woven wrap fabric. What differs between them is the weight range, how far the back panel adjusts, and whether the shoulder straps buckle or tie.
Which carrier lasts longest is usually decided by back panel height, not by weight. Most Standard carriers go to 44 lbs, which most children reach long after they have outgrown the panel.
DidyFix (Standard) - full buckle. Weight 7.5-44 lbs / 3.5-20 kg. Birth to about 2.5 years. Back panel 6-16 in wide, 10-13.5 in high. Waistband 29.5-59 in. Padded buckle shoulder straps 20.4-53.1 in. Back carry from about 4 months. No tying, fastest on and off.
DidyFix (Toddler) - full buckle. Weight 15-55 lbs / 7-25 kg. About 2 to 5 years. Back panel 10-18 in wide, 10-17 in high. Waistband 29.5-59 in. Padded buckle shoulder straps 20.4-53.1 in.
DidyFlow (Standard) - half buckle. Weight 7.7-44 lbs / 3.5-20 kg. From birth; back carry once baby has good head control. Back panel 7.1-15.7 in wide, 10.2-15.7 in high. Waistband 27.6-59.1 in. Padded wrap shoulder straps 72.8 in long and 3.5-5.5 in wide. The straps are shorter and slightly narrower than the DidyKlick and can be spread, though not as wide.
The DidyFlow's back panel adjusts higher than the DidyFix Standard or the DidyKlick Standard: 15.7 in against 13.5 in. If you want the most growth room in a Standard size, this is it.
DidyKlick (Standard) - half buckle. Weight 7.5-44 lbs / 3.5-20 kg. Birth to about 2.5 years. Back panel 6-16 in wide, 10-13.5 in high. Waistband 29.5-59 in. Wrap shoulder straps 86.6 in long and 12 in wide. Back carry from about 4 months.
DidyKlick (Toddler) - half buckle. Weight 15-55 lbs / 7-25 kg. About 2 to 5 years. Back panel 10-18 in wide, 10-17 in high. Back carry from about 2 years.
DidySnap (Standard) - full buckle. Weight 7.5-44 lbs / 3.5-20 kg. Birth to about 2.5 years. Back panel 6-16 in wide, 10-13.5 in high. Same panel range as the DidyFix Standard. Back carry from about 4 months.
DidyTai (Standard) - mei tai, all tie straps and no buckles. Weight 7.5-35 lbs / 3.5-16 kg. Birth to about 2.5 years. Back carry from about 4 months. Note that the DidyTai has a lower weight limit than the other Didymos carriers: 35 lbs rather than 44.
DidyGo Onbuhimo (Standard). Weight 15-44 lbs / 7-20 kg. About 6 months to 2.5 years, from sitting age. Back panel 14.5 in wide, 13 in high. Shoulder straps 13-34 in. No waistband, so front and back carries only.
DidySling ring slings and Didymos woven wraps. Weight 7-45 lbs / 3.5-20 kg, birth to 2+ years.
Choosing for growth room. If your child is close to outgrowing a Standard carrier's panel, the options with more room are the DidyFlow, whose panel goes to 15.7 in, or a Toddler size, whose panel goes to 17 in and which is rated 15-55 lbs.
Moving from one Standard carrier to another does not add growth room. The DidyKlick Standard, DidyFix Standard and DidySnap Standard all share the same 10-13.5 in panel, so switching between them changes how the carrier fastens, not how long it will fit your child.
If you are not sure which size your child needs, send us their age and weight and the carrier you have now, and we will check for you.