The 35 phases

A gentle map of your baby's first six years.

Instead of a generic age chart, Willo organises development into 35 named phases. Each is a window of a few weeks or months with its own rhythm, its own small magic, and its own kind of hard. Here is the full journey, from The Arrival to The Graduate.

Year 1 Year 2 Year 3 Year 4 Year 5
35
Phases
0 – 6
Years
Daily
Guidance
Why phases, not ages

A rhythm, not a checklist.

Babies don't follow a calendar. They follow biology. Phases are how we stop measuring against a generic timeline and start seeing who your baby is becoming.

The insight

Development happens in windows.

Your baby doesn't wake up on "month four" and learn to grab things. They move into a phase. Sometimes earlier, sometimes later. And then spend a few weeks developing a specific set of skills. Willo names each of these windows so you can recognise them, meet your baby where they are, and stop comparing them to averages.

The why

Rough weeks make sense inside a phase.

When your baby is fussy for no reason, or suddenly waking at night after months of sleeping through, or refusing food they loved yesterday. There's usually a phase behind it. The 35-phase map turns mystery into context. Inside the Willo app, each phase comes with daily guidance, phase-matched play, sleep support, and the tone of a mother who's been through it.

Find your phase

Which phase is my baby in?

Find your baby's age in the table and open that phase. Each one has typical sleep and feeding ranges for that exact window, what may be happening, and the questions parents ask most.

The 35 Willo phases, birth to age six, by age in days since birth.
Phase Name Age Days old Year
1The Arrival0–2 weeks0 to 14Year one
2Finding Focus2–4 weeks14 to 28Year one
3First Smiles4–6 weeks28 to 42Year one
4Discoverer6–8 weeks42 to 56Year one
5The Watcher2–3 months56 to 90Year one
6Finding Voice3–4 months90 to 120Year one
7The Grabber4–4.5 months120 to 135Year one
8The Roller4.5–5.5 months135 to 165Year one
9Sitting Up5.5–6.5 months165 to 195Year one
10The Explorer6.5–7.5 months195 to 225Year one
11On the Move7.5–8.5 months225 to 255Year one
12The Babbler8.5–9.5 months255 to 285Year one
13Little Cruiser9.5–10.5 months285 to 315Year one
14Problem Solver10.5–11 months315 to 335Year one
15Almost There11–12 months335 to 365Year one
16The Wobbler12–13 months365 to 395Year one
17Steady Steps13–15 months395 to 456Year two
18Little Scientist15–17 months456 to 517Year two
19The Mimic17–19 months517 to 578Year two
20Word Burst19–21 months578 to 639Year two
21Big Feelings21–23 months639 to 700Year two
22The Builder23–25 months700 to 760Year two
23Little Helper25–27 months760 to 821Year two
24Storyteller27–30 months821 to 912Year two
25Why? Why? Why?30–33 months912 to 1003Year three
26Adventurer33–36 months1003 to 1095Year three
27Making Friends3–3.5 years1095 to 1278Year three
28Imaginator3.5–4 years1278 to 1461Year three
29Negotiator4–4.25 years1461 to 1552Year four
30The Comedian4.25–4.5 years1552 to 1643Year four
31Deep Thinker4.5–4.75 years1643 to 1735Year four
32The Planner4.75–5 years1735 to 1826Year four
33Team Player5–5.25 years1826 to 1917Year five
34Ready to Read5.25–5.5 years1917 to 2008Year five
35The Graduate5.5–6 years2008 to 2190Year five
Year one

The first thirteen months.

16 phases from birth through the first wobbly steps.
Willo App Phase 01: The Arrival
Willo App · Phase 01
The Arrival
0–2 weeks

Brand new to the world. Every sound and every touch is a first.

Read this phase
Willo App Phase 02: Finding Focus
Willo App · Phase 02
Finding Focus
2–4 weeks

Vision sharpens as your baby begins to lock onto your face.

Read this phase
Willo App Phase 03: First Smiles
Willo App · Phase 03
First Smiles
4–6 weeks

The first real social smile arrives and changes everything.

Read this phase
Locked phase. Unlock inside the Willo App.
Willo App · Phase 04
Discoverer
6–8 weeks

Your baby discovers their own fingers for the first time.

Read this phase
Locked phase. Unlock inside the Willo App.
Willo App · Phase 05
The Watcher
2–3 months

A quiet observer. Attention lengthens and detail becomes fascinating.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 06
Finding Voice
3–4 months

Coos, squeals, and first real back-and-forth conversations.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 07
The Grabber
4–4.5 months

Hands become tools. Everything heads straight for the mouth.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 08
The Roller
4.5–5.5 months

Mobility begins. Back-to-tummy, tummy-to-back, often suddenly.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 09
Sitting Up
5.5–6.5 months

A new view of the world as hands are finally free.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 10
The Explorer
6.5–7.5 months

Everything within reach is a question worth answering.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 11
On the Move
7.5–8.5 months

Scooting, army-crawling, or pushing backward. Mobility in many shapes.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 12
The Babbler
8.5–9.5 months

Ba-ba, ma-ma, da-da. Consonants arrive for good.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 13
Little Cruiser
9.5–10.5 months

Pulling up and cruising along furniture, testing balance.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 14
Problem Solver
10.5–11 months

Objects used on purpose. Stacking, dropping, banging with intent.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 15
Almost There
11–12 months

The brink of walking. First words may emerge too.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 16
The Wobbler
12–13 months

First steps. Wobbly, proud, usually into your open arms.

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Year two

Walking, talking, feeling everything.

8 phases from 13 to 30 months.
Locked phase. Unlock inside the Willo App.
Willo App · Phase 17
Steady Steps
13–15 months

Walking is the new normal.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 18
Little Scientist
15–17 months

Cause, effect, and what-happens-if. The questions of the month.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 19
The Mimic
17–19 months

Everything you do is worth copying.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 20
Word Burst
19–21 months

Vocabulary suddenly explodes. New words almost daily.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 21
Big Feelings
21–23 months

Emotions bigger than the body holding them.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 22
The Builder
23–25 months

Stacks, towers, lines. Constructing and categorising the world.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 23
Little Helper
25–27 months

A genuine desire to help. Sweeping, pouring, carrying alongside you.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 24
Storyteller
27–30 months

Short sentences become little stories.

Read this phase
Year three

Questions, adventure, friends.

4 phases from 30 months through age 4.
Locked phase. Unlock inside the Willo App.
Willo App · Phase 25
Why? Why? Why?
30–33 months

The questions start and never really stop.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 26
Adventurer
33–36 months

Fearless climbing, running, jumping.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 27
Making Friends
3–3.5 years

Play becomes social. Other children become people, not objects.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 28
Imaginator
3.5–4 years

Dragons, tea parties, elaborate stories. Imagination takes the lead.

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Year four

Reason, humour, big ideas.

4 phases from age 4 to 5.
Locked phase. Unlock inside the Willo App.
Willo App · Phase 29
Negotiator
4–4.25 years

Trading, bargaining, reasoning for what they want.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 30
The Comedian
4.25–4.5 years

Silly jokes, goofy faces, made-up words.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 31
Deep Thinker
4.5–4.75 years

Quiet wondering about big questions.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 32
The Planner
4.75–5 years

Tomorrow becomes a concept. Plans and anticipates.

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Year five

Ready for the next chapter.

3 phases from age 5 to 6.
Locked phase. Unlock inside the Willo App.
Willo App · Phase 33
Team Player
5–5.25 years

Cooperative games and rules. Plays with, not just near.

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Locked phase. Unlock inside the Willo App.
Willo App · Phase 34
Ready to Read
5.25–5.5 years

Letters click. Sounds connect. Words make themselves known.

Read this phase
Locked phase. Unlock inside the Willo App.
Willo App · Phase 35
The Graduate
5.5–6 years

Six years have passed. The next chapter begins.

Read this phase

Get the full guidance for your baby's phase.

Each phase inside Willo opens into a full daily companion. Sleep support, phase-matched play, a warm AI assistant, a private memory book, and a community of mothers going through the exact same week. Free to install.

Download on the App Store