Devoted mother Jessica Fletcher found a way to ensure her nonverbal autistic son Hunter would never be left without a voice — by tattooing an image of a keyboard on her arm.

The idea — which has since spread to keyboard shirts and free tattoos for other parents of autistic kids — came from an everyday family crisis.

Jessica was out to eat with 11-year-old Hunter when the batteries in his Augmentative and Alternative Communication (AAC) device — a tablet that allows him to select words and symbols — suddenly died.

She got upset, but he didn’t blink an eye. Hunter grabbed a napkin, drew a keyboard on it and began pointing out his order.

For his mom, it was a lightning-bolt moment.

“That sparked the idea for me that I can’t limit him to technology because technology does fail us,” Fletcher told CTV News in Canada.

So she came up with a backup that would never run out of juice.

Jessica worked with a tattoo artist to ink a keyboard onto her forearm, complete with letters, a happy face, a sad face and an “I heart you” button.

The first word he typed when she revealed her surprise? “Mama.”

Now, so much of their communication frustration has been eliminated. Whenever they’re together, Hunter can simply tap out what he wants to tell his mother.

And there’s another sweet bonus: privacy.

Unlike Hunter’s communication device, which speaks his words out loud, the tattoo lets mother and son share quiet conversations.

Fletcher posted a video of Hunter using his mom’s arm to communicate via tattoo on Facebook on July 8., and it exploded online, racking up more than two million likes on social media, while also inspiring other families with nonspeaking loved ones.

“When we remove communication barriers, we’re giving non speakers the chance to show us who they really are,” Jessica told the Canadian news station.

The idea is now spreading far beyond one mother’s forearm.

Most touching of all, Hunter’s school friends want keyboard shirts, too, “so they can talk to him on the playground and be able to whisper and tell their secrets,” Fletcher said..

Jessica partnered with a clothing company to create shirts with keyboards printed down the sleeve. She says parents, nurses, doctors and first responders have reached out from around the world so they can help autistic kids in their schools, hospitals or families — while tattoo artists have offered to ink similar keyboards on parents for free.

For Jessica, the tattoo is a lifeline, a conversation and a simple, morale-boosting message that everyone — whether they can speak or not — would love to receive: “I hear you.”

And Jessica would do it all again.

“I’d give my body a thousand scars if it gave my son one more way to communicate,” she said.