Early Signs of Autism in Toddlers: What to Look For

Early signs of autism in toddlers usually show up in social communication: not pointing to share interest, rarely responding to their name, few gestures, little back-and-forth babbling or smiling, and limited pretend play. Repetitive movements, strong routines, and unusual reactions to sounds or textures are also common. One sign alone does not mean autism [1][2].

Why early signs of autism in toddlers are easy to miss

Most autistic toddlers sit, crawl, and walk on time. The differences tend to be in gestures, pretend play, and social use of language, which are subtle and easy to overlook, according to the American Academy of Pediatrics (AAP) [2]. Many parents only realize looking back that their child connected with the world a little differently in the first year.

Research that follows babies from birth shows why. In one study, babies later diagnosed with autism looked at faces, shared smiles, and made sounds to others about as often as other babies at 6 months. These behaviors then gradually declined, and clear differences were seen by 12 months [3]. In other words, the early signs of autism in toddlers often appear slowly over the first two years rather than all at once.

Early signs of autism in toddlers: social communication

The CDC lists signs of possible autism linked to typical ages [1]. Your child may:

• Not respond to their name by 9 months.
• Not show facial expressions like happy, sad, or surprised by 9 months.
• Not play simple back-and-forth games like pat-a-cake by 12 months.
• Use few or no gestures, such as waving bye-bye, by 12 months.
• Not share interests with you, such as bringing a toy to show you, by 15 months.
• Not point to show you something interesting by 18 months.
• Not notice when others are hurt or upset by 2 years.
• Not notice other children or join them in play by 3 years.

Joint attention: the skill behind many signs

Joint attention means looking back and forth between an object and another person to share the moment. The AAP calls delays in joint attention one of the most important differences between autistic and non-autistic children [2]. For example, by 18 months most children point at things they find interesting and check that you are looking too. An autistic toddler may point mainly to get something, or may take your hand and lead you to what they want without much eye contact [2].

Gestures matter too. In a study of baby siblings of autistic children, those later diagnosed used fewer gestures and understood fewer phrases at 12 months, and had delays in words and gestures at 18 months [4].

Language and play signs

Speech and play give more clues. Common early signs of autism in toddlers in this area include:

• Late or unusual talking. Many autistic toddlers have delayed speech. Some use words to label things but not to ask for things, or say words for objects before words for people [2].
• Echoing. Repeating words or lines from shows for a long time, often in the same tone of voice (called echolalia) [1]. Our guide to autism vs speech delay explains how this differs from a simple late start.
• Little pretend play. Not feeding a doll, pretending to talk on the phone, or copying everyday actions in play [5].
• Playing the same way every time. Lining up toys, spinning wheels, or focusing on parts of objects, and getting upset if the order changes [1].

The UK’s NICE guideline also lists, for preschool children, a language delay such as fewer than 10 words by age 2, reduced response to name despite normal hearing, reduced social smiling, and reduced imitation of others [5].

Repetitive behaviors and sensory signs

Early signs of autism in toddlers are not only social. The CDC and NHS also describe [1][6]:

• Flapping hands, rocking, spinning, or flicking fingers.
• Getting very upset by small changes in routine.
• Very strong interests in particular objects or topics.
• Over- or under-reacting to sounds, lights, smells, tastes, or textures, such as covering ears or seeming not to notice pain.
• Very selective eating based on texture, color, or brand.

Many toddlers do some of these things. When thinking about early signs of autism in toddlers, what matters is how often, how intense, and whether they come together with the social communication differences above.

Regression: when a toddler loses skills

Some autistic children develop some words or social skills and then stop using them. The AAP says this happens in about 1 in 4 children later diagnosed, usually between 15 and 24 months [2]. A meta-analysis of 85 studies found regression reported in about a third of autistic children, at an average age of about 21 months, with rates varying by how studies were done [7].

Loss of skills is never something to “wait and see” about. NICE advises that a child under 3 with regression in language or social skills should be referred to the autism team, and any child who loses motor skills should be seen by a pediatrician or pediatric neurologist [5].

Screening and checkups

The AAP recommends developmental surveillance at every well-child visit, formal developmental screening at 9, 18, and 30 months, and autism-specific screening at 18 and 24 months [8][9]. The most common autism screener is the M-CHAT-R/F, a parent questionnaire; see our guide to M-CHAT autism screening.

Siblings need extra attention. In a large international study, about 20% of younger siblings of autistic children were autistic themselves by age 3, so closer monitoring is advised [10].

What you can do at home

If you have spotted possible early signs of autism in toddlers, these steps help you gather information and support your child now.

• Use the CDC milestone checklists at 12, 15, 18, and 24 months. For example, by 18 months most children point to show you something and try to say three or more words besides “mama” or “dada” [11]. The checklists were revised in 2022 to use milestones that at least 75% of children reach by each age, partly to discourage a wait-and-see approach [12].
• Record short videos of anything that worries you, such as how your child plays or responds to their name.
• Play face to face. Get down to your child’s level, copy their sounds and actions, and pause to give them a turn.
• Name things together. When your child looks at something, look too and name it simply.
• Trust yourself. The AAP and CDC both say: you know your child best, and you should not wait if you are worried [13][11].

When to talk to a professional

Talk to your child’s doctor if your child is not meeting milestones, shows several of the signs above, or loses skills. Ask directly about developmental and autism screening. If concerns remain, ask for a referral to a specialist [14]. In the US you can contact your state’s early intervention program yourself; children under 3 do not need a diagnosis to be evaluated [15]. In the UK, speak to your GP or health visitor [6]. A hearing test is a sensible early step for any toddler with speech or response-to-name concerns [16].

Frequently asked questions

What is the earliest age autism signs can appear?

Research following babies from birth shows that differences in looking at faces, smiling, and babbling to others can start to emerge between 6 and 12 months in some children later diagnosed. Many signs become clearer in the second year, when pointing, showing, and first words are expected. The AAP notes autism can be diagnosed as young as 18 months, though many children are identified later.

My toddler lines up toys. Does that mean autism?

Not on its own. Many young children line up or sort toys, especially when learning about order and categories. It is more of a concern if it happens a lot, if your child becomes very upset when the line is moved, and if it comes along with social communication differences such as little pointing, showing, or response to name. If you are unsure, mention it at your next checkup.

Can a toddler make eye contact and still be autistic?

Yes. Some autistic toddlers make eye contact, especially with familiar people, and some smile and enjoy cuddles. Autism is diagnosed on a pattern of signs across social communication and repetitive behaviors, not on one single behavior. Clinicians look at how eye contact is combined with gestures, sounds, and sharing interest, so do not let good eye contact alone stop you raising other concerns.

Should I wait to see if my toddler grows out of it?

Experts advise against waiting. The CDC milestones were revised in 2022 partly to discourage a wait-and-see approach. Talking to your doctor early does not label your child; it gives you information and access to support. Early intervention programs can help with communication and development whether or not your child turns out to be autistic.

References

1. Centers for Disease Control and Prevention. Signs and Symptoms of Autism Spectrum Disorder. Last reviewed May 16, 2024. Link
2. American Academy of Pediatrics. 3 Early Signs of Autism in Children. HealthyChildren.org. Last updated September 26, 2025. Link
3. Ozonoff S, Iosif AM, Baguio F, Cook IC, Hill MM, Hutman T, et al. A prospective study of the emergence of early behavioral signs of autism. J Am Acad Child Adolesc Psychiatry. 2010;49(3):256-266. Link
4. Mitchell S, Brian J, Zwaigenbaum L, Roberts W, Szatmari P, Smith I, et al. Early language and communication development of infants later diagnosed with autism spectrum disorder. J Dev Behav Pediatr. 2006;27(2 Suppl):S69-S78. Link
5. National Institute for Health and Care Excellence. Autism spectrum disorder in under 19s: recognition, referral and diagnosis. Clinical guideline CG128. Published 28 September 2011; last updated 20 December 2017 (minor changes 2021-2025). Link
6. NHS. Signs of autism in children. Page last reviewed 6 May 2026. Link
7. Barger BD, Campbell JM, McDonough JD. Prevalence and onset of regression within autism spectrum disorders: a meta-analytic review. J Autism Dev Disord. 2013;43(4):817-828. Link
8. Lipkin PH, Macias MM; Council on Children With Disabilities, Section on Developmental and Behavioral Pediatrics. Promoting Optimal Development: Identifying Infants and Young Children With Developmental Disorders Through Developmental Surveillance and Screening. Pediatrics. 2020;145(1):e20193449. Link
9. Hyman SL, Levy SE, Myers SM; Council on Children With Disabilities, Section on Developmental and Behavioral Pediatrics. Identification, Evaluation, and Management of Children With Autism Spectrum Disorder. Pediatrics. 2020;145(1):e20193447. Link
10. Ozonoff S, Young GS, Bradshaw J, Charman T, Chawarska K, Iverson JM, et al. Familial Recurrence of Autism: Updates From the Baby Siblings Research Consortium. Pediatrics. 2024;154(2):e2023065297. Link
11. Centers for Disease Control and Prevention, Learn the Signs. Act Early. Milestones by 18 Months. Last reviewed May 16, 2026. Link
12. Zubler JM, Wiggins LD, Macias MM, Whitaker TM, Shaw JS, Squires JK, et al. Evidence-Informed Milestones for Developmental Surveillance Tools. Pediatrics. 2022;149(3):e2021052138. Link
13. Blitz R, Swoboda S. How Pediatricians Screen for Autism. HealthyChildren.org (American Academy of Pediatrics). Last updated March 7, 2025. Link
14. Centers for Disease Control and Prevention, Learn the Signs. Act Early. Milestones by 2 Years. Last reviewed May 16, 2026. Link
15. American Academy of Pediatrics. What is Early Intervention? HealthyChildren.org. Last updated December 23, 2025. Link
16. American Academy of Pediatrics Council on Children With Disabilities Autism Subcommittee. If Autism is Suspected, What’s Next? HealthyChildren.org. Last updated April 3, 2025. Link

This guide is general education, not medical advice. Always talk to your child’s doctor or care team. Last checked: October 2026.