Oral-B iO Series 4 Review: iO Cleaning Without the Screen, but Watch the £13 Heads
The iO4 is the cheapest iO with an app and the same magnetic motor as the expensive models. A national tester, a specialist toothbrush site and well over a thousand Argos buyers all rate the cleaning. The catch is not the handle, which almost nobody pays full price for — it is the brush heads, which cost several times what older Oral-B heads do and are the only ones that fit.
Where the reviews line up
The evidence comes from three places: a hands-on test by Expert Reviews, which made it a Best Buy; a long-term specialist test by Electric Teeth, which scores it 4.8/5; and the Argos buyer ratings on the black iO4 — 4.71/5 from 1,192 reviews on 5 October 2026. On the core question they agree.
It cleans like the expensive iOs. Expert Reviews calls the cleaning superb and the motor quiet; Electric Teeth rates it close to the top of its tests; Argos buyers keep using the phrase "dentist clean". The pressure ring works — a light around the neck that warns you when you press too hard — and the 2-minute timer pulses every 30 seconds so you move round the mouth. What you give up against an iO5 or iO6 is the handle's mode icons or screen, a fifth mode and, on the iO6, zone tracking. What you gain over an iO3 is Bluetooth and the app, plus a fourth mode.
The common complaint is running cost. iO heads are iO-only — the CrossAction heads that fit older Oral-B brushes do not fit. On the day we checked, Oral-B's own shop wanted £54 for four iO Ultimate Clean heads (£13.50 each) against £11.70 for four CrossAction (under £3 each). Shop around: Electric Teeth puts typical iO head prices nearer £8 each.
Two more things to know. Battery life is reported anywhere from two to three and a half weeks depending on who tested it, and the charger is a slow, ordinary Oral-B stand. And the price swings wildly: the £240 RRP is a fiction in practice, with the same handle at £80–£95 at major UK retailers on the day we looked.
The three reviews this summary is built from
- Expert ReviewsEditorial test by Stuart Andrews, April 2023. Best Buy award; reviewed at the £240 RRP.
- Electric TeethSpecialist toothbrush test by Jon Love, dated 17 May 2026. 4.8/5, 81/100; the deepest look at running costs.
- Argos4.71/5 from 1,192 buyer reviews on the black iO4, 5 October 2026 — hosted by a shop that sells it.
Before the review: where the iO4 sits, and the price you should pay
The iO4 is still on sale in the UK — Oral-B's own shop, Argos and Boots all listed it on 5 October 2026 — in black, white and lavender/purple, with or without a travel case. Oral-B's printed RRP is £240 (£270 for a bundle with two extra heads), but the shop itself was selling it at £95. Argos had the black handle at £90 and a purple version at £52.50. A deals site listed Boots at £80 with travel case, undated. Treat anything above about £100 as overpaying.
Specification at a glance
| Spec | Figure | Confidence |
|---|---|---|
| Cleaning modes | 4: Daily Clean, Whitening, Sensitive, Super Sensitive | Electric Teeth, Expert Reviews, Argos and Superdrug agree. One Argos listing (purple) says "gum care" instead — see below |
| Display | None — no screen and no mode icons on the handle | Electric Teeth, Expert Reviews, Tech Advisor |
| Pressure sensor | Light ring round the neck; motor slows if you press too hard | Colours given as white/green/red (Electric Teeth, Argos) and blue/green/red (Expert Reviews) |
| Timer | 2 minutes, with a pause every 30 seconds | Electric Teeth; Argos |
| Battery life | Electric Teeth: about 18 days claimed, 14–20 days measured. Expert Reviews: about 3.5 weeks, 1 hr 38 min continuous | Two tests disagree — both printed |
| Charger | Standard Oral-B charging stand, UK 2-pin bathroom plug, 1.2 m cable, up to 16 hours for a full charge | Electric Teeth; Expert Reviews says no fast charging. Oral-B's shop page says "magnetic fast charging" — see below |
| App | Optional. Bluetooth to the Oral-B app for brushing logs, pressure history, timer and head reminders. No zone tracking | Electric Teeth; Expert Reviews |
| Brush heads | iO heads only. iO Ultimate Clean 4-pack £54 at Oral-B (£13.50 each) | Oral-B shop, 5 Oct 2026. Older CrossAction heads, £11.70 for four, do not fit |
| Warranty | 2 years standard; register with Oral-B to extend to 3 years | Oral-B UK warranty page; retailers differ — see below |
| RRP | £240 (handle with travel case); £270 with two extra heads | Oral-B shop "was" prices; Electric Teeth and Tech Advisor also give £240 |
| UK price on the day | £52.50–£95 at major retailers | Oral-B shop £95, Argos £90 (black) and £52.50 (purple), Boots £80 (undated deals listing) — 5 Oct 2026 |
iO4 against its neighbours
| Model | Modes | Handle display | App | RRP |
|---|---|---|---|---|
| iO3 | 3 | None | No | £160 |
| iO4 | 4 | None | Yes | £240 |
| iO5 | 5 | Mode icons | Yes | £280 |
| iO6 | 5 | Monochrome screen | Yes, with 6-zone tracking | £299.99 |
From Tech Advisor's iO range comparison (Emma Rowley, 1 October 2026), checked 5 October 2026. All four use the same pressure light ring and the standard Oral-B charger; magnetic fast charging starts at the iO7. RRPs are list prices, not what any of these sell for.
Expert Reviews
Expert Reviews frames the iO4 as the way into the iO range without giving up the part that matters, and its verdict rests on cleaning: superb, from the same magnetic drive and micro-vibrating round head as the dearer models, and quieter than older Oral-B oscillating brushes. It reviewed the brush at its £240 list price but points out that it was already selling for around half that — which is how it ended up recommending it as excellent value.
The two downsides it names are the ones everyone names. There is no fast charging — just the basic two-pin Oral-B stand — and the replacement heads are expensive, at £20-plus for two and £30-plus for four when it looked. It measured 1 hour 38 minutes of continuous running, which it reads as about three and a half weeks of twice-daily brushing. It treats the app as optional but useful: it logs how long and how hard you brush, lets you change the colour of the ring, and gives technique tips. This test is from 2023, so its prices are old; the handle has not changed.
Watch: Oral-B iO Series 4 (iO4) Review
A full review of the same handle — the closest video match to a single-model editorial test. Confirmed by search listing; we could not open it.
Watch on YouTube ↗Electric Teeth
Electric Teeth tests nothing but toothbrushes, and its value here is the numbers. It confirms the four modes and that the handle shows none of them — you only see which mode you are in through the app, which is the clearest everyday difference from the iO5's icons and the iO6's screen. Against the iO3 the extra is Bluetooth, for about £50 more; against the iO5 and iO6 what is missing is real-time zone tracking.
On battery it is less generous than Expert Reviews: about 18 days claimed and between 14 and 20 measured, which it calls inconsistent. A full charge on the 1.2 m-cabled stand can take up to 16 hours. Its brush-head maths is the reason to read it: iO heads cost about twice a non-iO Oral-B head at around £8 each when bought sensibly, and it puts three years of ownership at about £208 including the handle at a typical £120. It also confirms the warranty is two years, extendable to three by registering. The app is not needed to brush — every core function, including the timer and pressure warning, works on the handle alone.
Watch: Oral-B iO Series 4 vs 5
A side-by-side of the iO4 and iO5 — the decision Electric Teeth spends most time on. Confirmed by search listing; we could not open it.
Watch on YouTube ↗Argos
These are owner ratings on pages that sell the product, so read the numbers rather than the tone. The black iO4 listing is the big sample and it is strong: 4.71 out of 5 across 1,192 reviews. The smaller purple listing is noticeably weaker at 3.9 from 47, though 96% would still recommend it, and its comments carry the main warning: several owners worry about battery life and longevity after the first months, and some report Bluetooth pairing trouble with the app. That matches one Oral-B shop reviewer whose battery was flat after three days.
The praise is consistent — a clean that feels like a dentist visit, and a pressure sensor and timer that people actually find useful. Two oddities on the purple listing: it names "gum care" among the modes and quotes 4,800 rotations a minute, neither of which matches Oral-B or the testers, so check the box of whatever you are sent. The black listing also says "manufacturer's 1 year guarantee", while the purple says three years when registered; Oral-B's own page says two, extendable to three.
Watch: Oral-B iO Series 4 Electric Toothbrush Review - Is It Worth It?
A "worth it?" review — the value question Argos buyers are answering. Confirmed by search listing; we could not open it.
Watch on YouTube ↗Strengths and weak points
What holds up
- Cleaning that testers and buyers put on a par with the dearer iO models.
- Quiet magnetic motor.
- Pressure light ring that slows the motor — useful for heavy-handed brushers.
- App is optional; timer and pressure warning work on the handle alone.
- Two-year warranty, three if you register with Oral-B.
- Routinely sells for well under half its £240 list price.
What people complain about
- iO-only heads: £13.50 each at Oral-B's own price, against under £3 for CrossAction.
- No display or icons, so you cannot see the mode without the app.
- Battery life reported between 14 days and 3.5 weeks; some owners worry about longevity.
- Slow, ordinary charging stand — up to 16 hours, no fast charge.
- Some Bluetooth pairing complaints.
- Prices jump around so much that buying on the wrong day costs you £40 or more.
Who it actually suits
Buy it if you want iO cleaning and the pressure warning, and you will pay around £80–£95 rather than anything near the list price. It is the sensible iO if you are curious about the app but do not need a screen telling you what mode you are in. Buy heads in multipacks when they are discounted, not one at a time.
Look elsewhere if running cost matters more than the newest motor: an older Oral-B brush on CrossAction heads costs a fraction as much to keep going. Skip down to the iO3 if you know you will never open the app, and step up to the iO6 only if you want zone tracking or a screen — and only at a discounted price.
What we could not check
- The videos. YouTube would not open from our research tools, so each video was confirmed by its exact address and title appearing in two differently worded searches. The search listings did not name the channels.
- Amazon and a live Boots price. We could not load either directly. The Boots £80 figure comes from an undated deals listing; Expert Reviews quoted £120 at Amazon, also undated.
- Superdrug. Its iO4 with travel case page says the product is no longer available online; the last price shown was £60, with 6,402 reviews but no score displayed.
- Battery life. Electric Teeth measured 14–20 days, Expert Reviews about 3.5 weeks. We cannot say which is closer to your use.
- Charging. Oral-B's own iO4 shop listing mentions "magnetic fast charging"; Expert Reviews says there is no fast charging and Tech Advisor puts the fast charger on the iO7 and above. We think the shop wording is wrong but could not confirm it with Oral-B.
- Pressure-ring colours. White/green/red according to Electric Teeth and Argos; blue/green/red according to Expert Reviews. The ring can be recoloured in the app, which may explain it.
- Warranty wording. Oral-B says two years, three if registered; one Argos listing says one year, another says three when registered; an Oral-B FAQ banner says "automatic 3 year warranty". Oral-B's page also ties the two-year standard to purchases after 26 September 2026 or from non-Oral-B shops. Register the brush whatever the box says.
- The purple Argos listing lists a "gum care" mode and 4,800 rotations a minute, which match no other source.
- The app. Tech Advisor's table lists the iO4 with app support while its text says connectivity starts at the iO5. Electric Teeth, Expert Reviews and Argos all confirm the iO4 has Bluetooth.
- Independent cleaning tests. We found no public Which? figure for the iO4.
Sources and prices last checked 5 October 2026. Oral-B prices change weekly — check the listing in front of you before ordering.