Autism vs Speech Delay: How to Tell the Difference

Autism vs speech delay often comes down to connection. A child with a simple speech delay is late to talk but usually communicates in other ways, such as pointing, showing, waving, and responding to their name. In autism, these nonverbal social skills also differ, and repetitive behaviors are common. Only an evaluation can tell for sure [1][2].

What counts as a speech delay?

Speech-language pathologists often describe a toddler as a “late talker” (late language emergence) when they have fewer than 50 words and no two-word phrases by 24 months, with no other diagnosed condition. The American Speech-Language-Hearing Association (ASHA) says this affects roughly 10% to 20% of 2-year-olds, is about three times more common in boys, and that around half to two-thirds of late talkers catch up with their peers [3].

The CDC milestones give a simpler check. By 2 years most children say at least two words together, like “more milk,” point to things in a book when asked, and use gestures beyond waving and pointing, such as nodding yes [4]. The UK NICE guideline lists fewer than 10 words by age 2 among the language features that can suggest possible autism, alongside other signs [5].

If language difficulties continue into school age without another explanation, a speech-language pathologist may diagnose developmental language disorder (DLD), the term agreed by an international expert panel [6].

Autism vs speech delay: the key differences

Words are only one part of communication. By 1 year, for example, most children wave bye-bye and play games like pat-a-cake [7]. The most useful way to think about autism vs speech delay is to look at everything else your child does to connect with you.

A child with a speech delay alone often:

• Points to show you things and looks back to check you saw them.
• Uses gestures like waving, reaching up, shaking their head, or nodding.
• Responds to their name and looks when you point.
• Brings toys to show you and enjoys back-and-forth games like peekaboo.
• Uses facial expressions and sounds to share feelings.
• Plays pretend games, such as feeding a teddy.

An autistic child may also:

• Point rarely, or mainly to get something rather than to share [1].
• Lead you by the hand to what they want, without much eye contact [1].
• Not respond to their name even though hearing is normal [5].
• Repeat words or lines from shows (echolalia) more than using words to ask or comment [8].
• Use words to label things but not to ask for things or to get your attention [1].
• Show repetitive movements, strong routines, or intense sensory reactions [8].

The World Health Organization’s ICD-11 guidance makes the same point: children with a language disorder are usually able to start and respond to social and emotional cues and share interests with others, and do not usually have restricted and repetitive behaviors, unlike autistic children [2].

Why the words themselves may look similar

When researchers matched autistic toddlers and late-talking toddlers on vocabulary size, the kinds of words they used and the complexity of their phrases were quite similar [9]. This is why counting words does not tell you much about autism vs speech delay. Gestures and social sharing are more telling: in baby siblings of autistic children, those later diagnosed used fewer gestures and understood fewer phrases at 12 months, and were behind in words and gestures at 18 months [10].

Understanding matters too. A review of late talkers found that a child’s receptive language (how much they understand), vocabulary size, and family circumstances helped predict later expressive language [11]. A toddler who understands a lot and communicates well without words has a better outlook for catching up.

It can be both

Autism and language delay are not either-or. Many autistic children also have delayed spoken language, and ICD-11 records the level of functional language as part of an autism diagnosis [2]. Some autistic children talk on time but use language in unusual ways, such as talking like an adult or repeating scripts [1]. A good assessment looks at language, social communication, play, and behavior together.

Other things can also cause late talking, including hearing loss, global developmental delay, and, rarely, motor speech difficulties. The AAP notes that hearing loss needs to be considered in any child with language delay [12].

How professionals tell autism vs speech delay apart

No single test separates the two. Clinicians put together several pieces of information [12][13]:

• A hearing test, to rule out hearing loss as a cause of late talking.
• A developmental history from you, covering when skills appeared, how your child communicates, and any loss of skills.
• A speech-language evaluation of understanding, expressive language, gestures, and play.
• Structured observation of social communication and play, sometimes using autism-specific tools.
• Information from other settings, such as daycare or preschool.

NICE advises that no autism-specific tool should be used alone to make or rule out a diagnosis, and that diagnosis can be less certain in children under 2 [5]. Sometimes a professional will suggest support now and a review in a few months. That is a reasonable plan when the picture is unclear, as long as support starts in the meantime. Over time, how a child responds to speech therapy and how their social skills develop often makes the answer to autism vs speech delay much clearer.

What you can do at home

Whatever the answer to autism vs speech delay turns out to be, these everyday strategies support communication.

• Notice the nonverbal. For a week, jot down how your child asks for things, shows you things, and responds when you call or point.
• Talk about what they are doing. Use short phrases about what your child is looking at or playing with, such as “big ball,” “ball rolls.”
• Pause and wait. After you speak, wait a few seconds with an expectant look to give your child a turn to respond in any way.
• Follow their lead in play. Join in with what interests them rather than redirecting. Connecting through play helps communication in both late talkers and autistic children [14].
• Accept all communication. Gestures, signs, sounds, and pictures are all valid ways to communicate and do not stop speech from developing.

When to talk to a professional

Speak to your child’s doctor if your child is not meeting the CDC milestones, has lost words, or shows the social differences described above. Ask for [14][4]:

• A hearing test.
• A developmental and autism screen, such as the M-CHAT-R/F (see M-CHAT autism screening).
• A speech-language evaluation.
• A referral to your state’s early intervention program if your child is under 3. You can also call them yourself, and no diagnosis is needed [15].

Losing words or social skills at any age should be checked quickly rather than watched [5]. For more signs to look for, see early signs of autism in toddlers.

Frequently asked questions

Is a speech delay a sign of autism?

It can be, but most late talkers are not autistic. Many autistic children do have delayed speech, so late talking is one reason doctors consider autism. The difference lies in other skills: a child with a simple speech delay usually points, gestures, shares smiles, and responds to their name. If those skills are also limited, ask your doctor about an autism screen.

At what age should I worry about my child not talking?

Talk to your doctor if your child is not babbling or using gestures by 12 months, is not trying to say three or more words by 18 months, or is not combining two words by 2 years. These are based on CDC milestones that most children reach by those ages. Any loss of words at any age needs prompt attention.

Can a late talker who points and waves still be autistic?

It is possible, because autism shows up differently in each child, but good pointing, showing, and waving are reassuring signs. Clinicians look at a pattern across social communication, play, and repetitive behaviors. If your child communicates well without words and has no other concerns, a speech delay alone is more likely, but a professional check is still worthwhile.

Will speech therapy help if we don’t know yet whether it is autism?

Yes. Speech-language therapy and early intervention can start before any diagnosis, and the strategies help children with many kinds of communication difficulty. A therapist can also observe your child over time, which may help clarify whether an autism assessment is needed. In the US, children under 3 can be evaluated by early intervention without a diagnosis.

References

1. American Academy of Pediatrics. 3 Early Signs of Autism in Children. HealthyChildren.org. Last updated September 26, 2025. Link
2. World Health Organization. Clinical descriptions and diagnostic requirements for ICD-11 mental, behavioural and neurodevelopmental disorders (CDDR). Geneva: WHO; 2024. ISBN 9789240077263. Section 6A02 Autism spectrum disorder. Link
3. American Speech-Language-Hearing Association. Late Language Emergence (Practice Portal). Link
4. Centers for Disease Control and Prevention, Learn the Signs. Act Early. Milestones by 2 Years. Last reviewed May 16, 2026. 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. Bishop DVM, Snowling MJ, Thompson PA, Greenhalgh T; CATALISE-2 consortium. Phase 2 of CATALISE: a multinational and multidisciplinary Delphi consensus study of problems with language development: Terminology. J Child Psychol Psychiatry. 2017;58(10):1068-1080. Link
7. Centers for Disease Control and Prevention, Learn the Signs. Act Early. Milestones by 1 Year. Last reviewed May 16, 2026. Link
8. Centers for Disease Control and Prevention. Signs and Symptoms of Autism Spectrum Disorder. Last reviewed May 16, 2024. Link
9. Ellis Weismer S, Gernsbacher MA, Stronach S, Karasinski C, Eernisse ER, Venker CE, et al. Lexical and grammatical skills in toddlers on the autism spectrum compared to late talking toddlers. J Autism Dev Disord. 2011;41(8):1065-1075. Link
10. 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
11. Fisher EL. A Systematic Review and Meta-Analysis of Predictors of Expressive-Language Outcomes Among Late Talkers. J Speech Lang Hear Res. 2017;60(10):2935-2948. Link
12. 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
13. Centers for Disease Control and Prevention. Clinical Testing and Diagnosis for Autism Spectrum Disorder. Last reviewed May 8, 2025. Link
14. 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
15. American Academy of Pediatrics. What is Early Intervention? HealthyChildren.org. Last updated December 23, 2025. Link

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