Best Insoles for Sandals: Is Arch Support Possible in Open Shoes?

Hands pressing an orthotic insole into an open sandal on a bright outdoor surface

Adding arch support to sandals is possible in more shoe types than most people expect, as long as the insole is designed for it.

Sandals are the footwear most people reach for in warmer months, and the one type of shoe that typically offers the least arch support. Most sandal footbeds are flat, thin, and designed purely around aesthetics or basic cushioning. For anyone whose feet are already dealing with arch fatigue, heel soreness, or general foot pain, switching to sandals for the summer can make symptoms noticeably worse.

The obvious solution (adding an insole) runs into an immediate problem with most sandals: there is no enclosed upper to hold an insole in place. Slip an ordinary insole into a strappy sandal and it will shift, bunch, or slide out entirely within a few steps. That limitation has led a lot of people to assume that arch support in open shoes simply is not possible.

The short answer is that it is possible, but it depends on the sandal type and the insole. This article covers which sandals can accommodate proper support, what to look for in a sandal insole, and how the right design solves the fit problem that regular insoles cannot.

Quick answer: can you get arch support in sandals?

Yes, but the approach depends on the sandal. Deeper-bed walking sandals and espadrilles can usually accept a slim 3/4-length insole. Flat, strappy, or low-profile sandals need a different solution: a slim insole with a full-length adhesive backing that bonds to the footbed rather than relying on an enclosed upper to stay in place. Without adhesive, an insole in an open shoe will not stay put.

Why sandals are hard on feet

A standard sandal footbed is a flat piece of foam or cork sitting directly under the foot with nothing supporting the arch. Every step you take loads the plantar fascia, heel fat pad, and arch muscles without any external structure to share that work.

This is manageable for short periods on soft surfaces. It becomes a real problem over long days of walking, standing on hard pavement, or for anyone with flat feet or fallen arches. The arch tires, the heel takes more impact, and by the end of the day, feet that felt fine in the morning are sore and swollen.

People who wear supportive footwear for most of the year sometimes find that switching to sandals for a few weeks triggers plantar fasciitis flare-ups or heel pain they had not experienced in months. The connection is direct: the support they had been relying on disappears the moment they put sandals on. Our guide to why flip-flops and flat summer shoes cause so many problems covers the mechanics in more detail.

Which sandal types can accommodate an insole

Not every sandal is a candidate, and being honest about this matters more than overselling the solution.

Walking sandals and sport sandals with a deep, contoured footbed and adjustable straps usually have enough depth and structure to hold a 3/4-length insole securely, especially if the footbed is removable.
Espadrilles and wedge sandals with a thick sole often have enough room for a slim insole without raising the foot uncomfortably against the straps.
Flat strappy sandals, mules, and slides have no enclosed upper, so an ordinary insole will not stay in place. These require an insole with adhesive backing to bond directly to the footbed.
Thong sandals and flip-flops are the most limited. Very thin footbeds leave almost no room for any insole. A slim adhesive insole can work in quality leather or rubber thong sandals with a slightly thicker footbed, but ultra-thin flip-flops are difficult to support with any insole.

The deciding factor in the second and third category is always the adhesive. Without it, the insole moves. With it, open sandals become a viable option for arch support in a way that was not previously practical for most people.

Side-by-side comparison of a deep-bed walking sandal suited to a 3/4 insole and a flat strappy sandal suited to a slim adhesive insole

Deeper-bed sandals can usually hold a 3/4-length insole without adhesive. Flat and strappy sandals need a slim insole with a full-length adhesive backing to stay in place.

What to look for in a sandal insole

A sandal insole has to solve problems that a regular shoe insole does not face. It needs to be slim enough to fit without pushing the foot too high against the straps, have meaningful arch support despite that slim profile, and stay firmly in place without an enclosed upper holding it in.

The features that matter most:

Full-length adhesive backing. This is the critical feature for open sandals. An insole that bonds to the footbed stays put through an entire day of wear and does not shift during walking. Without this, any insole in an open shoe is unreliable.
A slim, low-profile design. A thick insole raises the foot and creates pressure against straps and toe posts. A slim orthotic profile provides arch support and heel cushioning within the depth the sandal actually has.
Structured arch support, not just cushioning. A soft foam pad adds a little comfort but does not meaningfully unload the plantar fascia or support the midfoot. A structured arch contour actively reduces the strain on the arch with each step.
Forefoot coverage. For sandals where ball of foot discomfort is a factor, an insole that extends to the forefoot provides more complete support than one that covers only the heel and arch.

Which Footminders insoles work in sandals

Two Footminders insoles are suited to different sandal types, and matching the right one to the sandal is straightforward once you know what you are working with.

For flat, strappy, and low-profile sandals where a regular insole will not stay in place, Footminders Catwalk is the right choice. Originally designed for heeled and low-volume shoes like ballet flats, Catwalk has a full-length adhesive patch along its entire underside. That adhesive bonds the insole to the sandal footbed so it stays firmly in place regardless of strap configuration or open sides. The slim profile means it fits within the shallow depth most sandals have, and the structured arch contour provides meaningful support despite that low height.

For walking sandals, sport sandals, and espadrilles with a deeper footbed, Footminders Casual is usually the better fit. The 3/4-length design provides arch support and a cushioned heel without adding bulk under the toes, and it sits securely in sandals that have enough depth and structure to hold it in place without adhesive.

Footminders Catwalk

Slim orthotic insole with a full-length adhesive backing that bonds to the sandal footbed. The adhesive keeps it firmly in place in flat, strappy, and open sandals where a regular insole would shift. Provides structured arch support and cushioning in a low-profile design.

View Catwalk Insoles

Footminders Casual

3/4-length orthotic insole for walking sandals, sport sandals, and espadrilles with enough footbed depth to hold an insole without adhesive. Provides arch support and heel cushioning without adding bulk under the toes.

View Casual Insoles

Related guides

FAQ

Can you put insoles in sandals?

Yes, but the approach depends on the sandal type. Deeper-bed walking sandals and espadrilles can usually hold a slim 3/4-length insole without adhesive. Flat, strappy, and open sandals need an insole with a full-length adhesive backing that bonds to the footbed. Without adhesive, an insole in an open sandal will shift out of place during wear.

Why do my feet hurt more in sandals than in regular shoes?

Sandals typically have flat footbeds with no arch contour, no heel cushioning structure, and no support for the midfoot. This makes the arch and plantar fascia work harder with each step. People who rely on supportive footwear during cooler months often notice the difference immediately when they switch to sandals in summer.

How does an adhesive insole stay in place in an open sandal?

An insole with a full-length adhesive patch along its underside bonds directly to the sandal footbed. Because it is held in place by adhesion rather than by the shoe's upper, it stays firmly in position in open, strappy, and low-profile sandals where a regular insole would slide or bunch during walking.

What type of sandals work best with insoles?

Walking sandals, sport sandals, and espadrilles with a deeper, more structured footbed work well with a slim 3/4-length insole. Flat strappy sandals, mules, and slides work with a slim adhesive insole. Very thin flip-flops with minimal footbed depth are the most difficult to support with any insole, though a quality leather or rubber thong sandal with a thicker sole can often accommodate a slim adhesive option.

Will adding an insole make sandal straps feel too tight?

A slim, low-profile insole adds minimal height, usually a few millimetres. In most sandals this is not enough to meaningfully affect strap tension. The exception is sandals that already fit very snugly across the top of the foot. If adjustable straps are present, loosening them slightly after inserting the insole usually resolves any tightness.

Medical references

OrthoInfo (AAOS): Foot pain and problems

Final takeaway

Arch support in sandals is genuinely possible, but the type of insole has to match the sandal. For open and strappy styles, the adhesive is what makes it work: without it, no insole will stay in place long enough to do any good. For deeper-bed walking sandals, a slim 3/4-length insole sitting in the footbed is usually enough. Either way, adding structured support to summer footwear is one of the simplest steps you can take to reduce the arch fatigue and heel soreness that flat sandals tend to cause over a full day of wear.