How to use this case study
This post runs Xiaomi's four current India air purifiers, the Mijia 4 Compact, the Air Purifier 4 Lite, the Air Purifier 4 and the flagship Mijia 6, through our Buying Checklist. Every row below maps directly to the interactive Buying Checklist toolso you can follow along and fill in your own evaluation as you read. Every section now scores all four machines side by side, and the combined scorecard and buying advice further down turn those rows into a decision.
Sources: Xiaomi India official specs and GB/T 18801-2015 standard. You can also compare with our Dyson HJ10 case study, the Honeywell Air Touch walkthrough, the Coway AirMega range or the Philips PureProtect Quiet 2200.
Key terms used in this post
HEPA filter, HEPA-type media, CADR, ACH, activated carbon filter, ioniser and ozone are explained in the glossary.
Disclaimer: This is an independent case study for educational purposes only, not a promotion or endorsement of Xiaomi products. We have no affiliation with Xiaomi or any air purifier brand.
Quick specs at a glance: all four Xiaomi machines
Xiaomi's India range now runs from the ₹7,999 Mijia 4 Compact to the ₹19,999 Mijia 6. All figures below are from mi.com/in. Honest coverage is our own figure: the floor area a machine can actually keep clean at a 10 ft ceiling and 5 air changes per hour, after a 25% real-world buffer, which is the standard we apply everywhere on this site.
| Spec (mi.com/in) | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 |
|---|---|---|---|---|
| Model | AC-M18-SC | AP4 Lite | AP4 | AC-M25-SC |
| Price (OEM) | ₹7,999 | ₹12,999 | ₹15,999–17,999 | ₹19,999 |
| Particle CADR | 230 m³/h | 360 m³/h | 400 m³/h | 443 m³/h |
| Claimed coverage | Up to 400 sq.ft at 2 ACPH | Up to 463 sq.ft | Up to 516 sq.ft | Up to 940 sq.ft at 2 ACPH |
| Honest coverage (10 ft, 5 ACH, 25% buffer) | ~122 sq.ft | ~190 sq.ft | ~212 sq.ft | ~235 sq.ft |
| Filter media | HEPA, grade not printed | High-Efficiency Filter | High-Efficiency Filter | 99.98% at 0.3 µm, grade not printed |
| Activated carbon | Yes (3-layer stack) | 450,000 mg | 500,000 mg | Yes |
| PM2.5 display | Not published | LED, PM2.5 | OLED, PM2.5 | LCD, 5 sensors |
| Noise (sleep) | 20 dB(A) | 33.4 dB(A) | 32.1 dB(A) | 32 dB(A) |
| Power (max) | 27 W | ~33 W | ~33 W | 40 W |
| Ioniser / UV-C | Neither | Neither | Ioniser, can disable | UV-C + ion, vetoed |
| Checklist score | 14 / 19 | 16 / 19 | 16 / 19 | Do not buy |
Not sure what CADR you need for your room? Use our Air Purifier CADR Calculator to find the right size in under a minute.
1. Room Sizing
| Checklist Item | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 | Notes |
|---|---|---|---|---|---|
| Room volume calculated | Yes | Yes | Yes | Yes | Prerequisite step: measure your room before comparing CADR figures. |
| CADR matches required ACH (5 air changes/hr) | Yes | Yes | Yes | Yes | All four publish a numeric particle CADR: 230 m³/h (Mijia 4 Compact), 360 m³/h (AP4 Lite), 400 m³/h (AP4) and 443 m³/h (Mijia 6). Match that figure to your own room volume rather than the marketing coverage claim. |
| Purifier slightly oversized (~20–30%) | Needs attention | Needs attention | Needs attention | Yes | Honest coverage at a 10 ft ceiling, 5 ACH and a 25% real-world buffer: ~122 sq.ft. (Mijia 4 Compact), ~190 sq.ft. (AP4 Lite), ~212 sq.ft. (AP4) and ~235 sq.ft. (Mijia 6). Only the Mijia 6 leaves real headroom in a typical Indian bedroom, and it is vetoed on other grounds. |
Coverage area deep-dive
GB/T 18801 tests are conducted in a sealed, unfurnished ~30 m³ chamber. Real homes have furniture, gaps under doors, and people moving, all of which reduce effective CADR. For Delhi/NCR where AQI regularly exceeds 200, always size against the lower end and apply a 20–30% buffer.
| Parameter | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 |
|---|---|---|---|---|
| Particle CADR (manufacturer rated) | 230 m³/h | 360 m³/h | 400 m³/h | 443 m³/h |
| Manufacturer claimed coverage | Up to 400 sq.ft. (2 ACPH) | Up to 463 sq.ft. | Up to 516 sq.ft. | Up to 940 sq.ft. (2 ACPH) |
| CADR after 25% real-world buffer | 173 m³/h | 270 m³/h | 300 m³/h | 332 m³/h |
| Practical coverage at 5 ACH (9 ft ceiling, shown only for comparison) | ~13 m² (~136 sq.ft.) | ~19–20 m² (~212 sq.ft.) | ~21–22 m² (~236 sq.ft.) | ~24 m² (~261 sq.ft.) |
| Practical coverage at 5 ACH (10 ft ceiling) | ~11 m² (~122 sq.ft.) | ~17–18 m² (~190 sq.ft.) | ~19–20 m² (~212 sq.ft.) | ~22 m² (~235 sq.ft.) |
| Verdict for large rooms (>30 m²) | Too small | Insufficient, upgrade recommended | Borderline, consider larger unit | Adequate, but vetoed |
2. Filters
| Checklist Item | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 | Notes |
|---|---|---|---|---|---|
| True HEPA (H13/H14 preferred) | Needs attention | Needs attention | Needs attention | Needs attention | No machine in the range prints an H13 or H14 grade. AP4 and AP4 Lite use 'High-Efficiency Filter' branding rated 99.99% at 0.1 μm; the Mijia 4 Compact says HEPA without a grade; the Mijia 6 says 99.98% at 0.3 µm. |
| Activated carbon filter | Yes | Yes | Yes | Yes | All four list a carbon stage. Whether the quantity is published is assessed separately in the carbon thickness row below. |
| Washable pre-filter | No | No | No | No | Every model uses an all-in-one cartridge with the pre-filter integrated, so none of them has a separately washable pre-filter. |
| Filter replacement cost checked | Needs attention | Yes | Yes | Needs attention | AP4 Lite filter ~₹2,980 on mi.com India, AP4 similar, both with a 6–12 month interval. Neither Mijia page lists a cartridge price at the time of writing, so the running cost cannot be verified from official data. |
| Adequate carbon thickness | Needs attention | Yes | Yes | Needs attention | Only AP4 and AP4 Lite publish a carbon mass (500,000 mg and 450,000 mg). Neither Mijia page gives a quantity, so odour and VOC capacity cannot be verified from official data. |
3. Sensors & Modes
| Checklist Item | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 | Notes |
|---|---|---|---|---|---|
| Real-time PM2.5 display | No | Yes | Yes | Yes | AP4: OLED touch display. AP4 Lite: LED display with colour strip. Mijia 6: LCD fed by five sensors. Mijia 4 Compact: no numeric PM2.5 readout published. |
| TVOC sensor | No | No | No | Yes | Only the Mijia 6 lists a wider sensor array including gas sensing; the other three list a particle sensor only. |
| Night / Sleep mode | Yes | Yes | Yes | Yes | Sleep noise: 20 dB(A) (Mijia 4 Compact), 33.4 dB(A) (AP4 Lite), 32.1 dB(A) (AP4), 32 dB(A) (Mijia 6). All sit under the 35 dB bedroom threshold. |
| Auto mode | Yes | Yes | Yes | Yes | All four auto-adjust fan speed from the on-board particle sensor. |
4. Performance
| Checklist Item | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 | Notes |
|---|---|---|---|---|---|
| Verified CADR (AHAM or trusted tests) | Needs attention | Needs attention | Needs attention | Needs attention | All four are rated to GB/T 18801-2015 (China Testing & Inspection Institute), not AHAM. The number is published, which is what the checklist requires, but the test standard is not the stricter one. |
| Noise level acceptable | Yes | Yes | Yes | Yes | The Mijia 4 Compact is the quietest on paper at 20 dB(A), though it is also the weakest machine. The rest cluster around 32–33 dB(A) on sleep mode. |
| Power consumption reasonable | Yes | Yes | Yes | Yes | 27 W (Mijia 4 Compact), ~33 W (AP4 and AP4 Lite), 40 W (Mijia 6). Run continuously at ₹8 per unit, that is roughly ₹1,900 a year for the Compact and ₹2,800 a year for the Mijia 6. |
5. Usability
| Checklist Item | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 | Notes |
|---|---|---|---|---|---|
| Filter change indicator | Yes | Yes | Yes | Yes | All four report filter life in the Xiaomi Home / Mi Home app with replacement reminders. |
| App / Wi-Fi | Yes | Yes | Yes | Yes | App control plus Alexa and Google Assistant across the range. Basic on-device controls work without the app. |
| Replacement filters available in India | Needs attention | Yes | Yes | Needs attention | AP4 and AP4 Lite cartridges are widely stocked on mi.com India and marketplaces. The two Mijia machines are newer, so filter availability outside metro cities is worth confirming before you buy. |
6. Cost & Service
| Checklist Item | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 | Notes |
|---|---|---|---|---|---|
| 3-year total cost calculated | Yes | Yes | Yes | Yes | Roughly ₹19,000 (Mijia 4 Compact), ₹27,000 (AP4 Lite), ₹29,000 (AP4) and ₹34,000 (Mijia 6) over three years. Assumes the unit price, two filter changes and continuous running at ₹8 per unit. |
| Warranty of 1–2+ years | Needs attention | Needs attention | Needs attention | Needs attention | Every model carries only a 1-year warranty, with consumable filters excluded. |
| Service network available | Needs attention | Needs attention | Needs attention | Needs attention | Check with the company for local service centre availability and post-warranty repair support before purchase. |
7. Things to Avoid
| Checklist Item | Mijia 4 Compact | AP4 Lite | AP4 | Mijia 6 | Notes |
|---|---|---|---|---|---|
| Free of a negative ioniser | Yes | Yes | Needs attention | Avoid | Mijia 4 Compact and AP4 Lite: no ioniser listed. AP4: a negative ioniser is listed but can be switched off in the app, so it is not a veto. Mijia 6: a negative ion function is marketed as part of PentaClean, which is a hard veto. |
| Free of UV-C as a cleaning stage | Yes | Yes | Yes | Avoid | Only the Mijia 6 lists UV-C sterilisation as a cleaning stage. The other three rely on filtration alone. |
| Free of "HEPA-type" or "HEPA-like" labelling | Needs attention | Needs attention | Needs attention | Needs attention | None of the four uses HEPA-type wording, but none prints a formal H13 or H14 grade either, which is why every column needs attention rather than a clean yes. See the Filters section above for what each page actually claims. |
| Free of plant-based or VOC-only cleaning claims | Yes | Yes | Yes | Yes | None of the four makes such claims, good. |
Why the Mijia 6 is vetoed before it is scored
Our checklist is veto-first. Four faults are disqualifying, and a machine that trips any one of them is never scored at all, however good the rest of its specification looks:
- No numeric CADR published by the manufacturer.
- "HEPA-type" or "HEPA-like" media instead of a real pleated HEPA filter.
- No activated carbon stage.
- An ioniser, plasma or UV-C lamp used as the extra cleaning technology.
The fourth veto is the one the Mijia 6 trips. Xiaomi's own India page lists UV-C sterilisation and a negative ion function as part of its PentaClean system. Both are ozone-adjacent: ionisers can generate ozone as a by-product, and in-duct UV-C at domestic air speeds contributes very little measurable particle or gas removal while adding a lamp that ages invisibly. Ozone is a respiratory irritant, so we do not rank machines that make it a selling point, and we do not let a strong CADR figure buy forgiveness for it. The Mijia 6 also describes its filter as 99.98% at 0.3 µm rather than printing an H13 or H14 grade, so even without the first problem it would have lost points on transparency.
The AP4 is a deliberate contrast. It carries a negative ioniser too, but Xiaomi exposes an off switch in the Xiaomi Home app, so ionisation is an optional extra rather than the cleaning method. That is a "switch it off and forget it" machine, not a veto. On the Mijia 6, UV-C and ionisation are marketed as core purification stages.
The same rule runs inside our Find an Air Purifier engine, which is why the Mijia 6 sits in the catalogue but never appears in results. Read the reasoning in full in the buying checklist guide.
The checklist scorecard
The same scoring sheet used by the interactive buying checklist and our Find an Air Purifier tool. Scores start at 0 and run to 19 (an optional in-stock point takes the tool's sheet to 20). Vetoes are applied first: no numeric OEM CADR, "HEPA-type" labelling, no carbon filter, or an ioniser / UV-C as the extra cleaning technology means do not buy, and the machine is not scored at all.
| Criterion | AP4 | AP4 Lite | Mijia 4 Compact | Mijia 6 |
|---|---|---|---|---|
CADR meets need (5 ACH, correctly sized room) 400, 360, 230 and 443 m³/h; size from CADR, not the headline coverage claim | 5 / 5 | 5 / 5 | 5 / 5 | 0 / 5 |
H13 / H14 printed on the spec sheet None of the four prints a European grade; the AP4 pair uses 'High-Efficiency Filter', the Compact says HEPA without a grade, the 6 quotes 99.98% at 0.3 µm | 1 / 2 | 1 / 2 | 1 / 2 | 0 / 2 |
Activated carbon bed 500,000 mg (AP4), 450,000 mg (Lite), three-layer stack with carbon on the Compact | 2 / 2 | 2 / 2 | 2 / 2 | 0 / 2 |
Noise ≤ 30 dB on the lowest mode 32.1, 33.4, 20 and 32 dB(A) in sleep mode | 1 / 2 | 1 / 2 | 2 / 2 | 0 / 2 |
India warranty + service network 1-year warranty across the range; verify local service-centre availability | 1 / 2 | 1 / 2 | 1 / 2 | 0 / 2 |
PM2.5 numeric display AP4 OLED and Lite LED both show a PM2.5 number; the Compact publishes no air-quality sensor | 2 / 2 | 2 / 2 | 0 / 2 | 0 / 2 |
App / Wi-Fi control Xiaomi Home on all four, with Google Home and Alexa support | 2 / 2 | 2 / 2 | 2 / 2 | 0 / 2 |
Filter indicator or washable pre-filter In-app filter-life tracking on all four and no washable pre-filter on any of them; the Compact loses a point because Xiaomi publishes no cartridge price or replacement listing for it in India | 2 / 2 | 2 / 2 | 1 / 2 | 0 / 2 |
| Total / 19 | 16 | 16 | 14 | Not scored |
| Veto | — | — | — | UV-C sterilisation and negative ion as core cleaning stages |
AP4 and AP4 Lite both land on 16/19. Mijia 4 Compact lands on 14/19: honest, very quiet, genuinely small-room, and losing points only where Xiaomi publishes nothing. Mijia 6 is vetoed and therefore not scored. If Xiaomi makes the UV-C and ioniser permanently switchable and prints a filter grade, we will rescore it.
Who should buy which?
Mijia 4 Compact — 14/19
₹7,999 · 230 m³/h · honest coverage ~122 sq.ft
- Your room is a small bedroom, study or nursery under ~120 sq.ft
- Silence matters more than a display: 20 dB(A) is the quietest here
- You are happy to read air quality from a phone or a separate monitor
- You want the lowest entry price without dropping the carbon stage
AP4 Lite — 16/19
360 m³/h · honest coverage ~190 sq.ft
- Your room is up to about 18 m² at a 10 ft ceiling
- You want to avoid the ioniser question entirely
- Budget matters and VOC or odour concerns are mild
- You still want an on-device PM2.5 number
AP4 — 16/19
400 m³/h · honest coverage ~212 sq.ft
- Your room is up to about 20 m² at a 10 ft ceiling
- You need the higher carbon capacity (500,000 mg vs 450,000 mg)
- You want the OLED touch display
- You are willing to disable the ioniser in the app on day one
Mijia 6 — do not buy
₹19,999 · 443 m³/h · vetoed, not scored
- UV-C and negative ion are marketed as core purification stages
- No printed H13 or H14 grade, only a 99.98% at 0.3 µm claim
- The five-sensor readout is genuinely good, but it does not lift a veto
- For the same room, buy a larger plain HEPA-plus-carbon machine instead
Coverage claims on all four pages are quoted at about 2 air changes per hour. Indian homes in a polluted season need 5, which is why our honest coverage figures land at roughly a quarter to two-fifths of the headline numbers. Check your own room with the CADR calculator before you shortlist anything.
The verdict across the range
Xiaomi's India line-up now spans ₹7,999 to ₹19,999, and the checklist separates it cleanly. The three machines that stick to pre-filter, HEPA and carbon score 14 to 16 out of 19, losing points in the same three places every time: no printed filter grade, a single year of warranty, and sleep-mode noise just above 30 dB(A) on the two larger units. Those are transparency and finish gaps, not safety problems.
The flagship is the outlier. The Mijia 6 has the strongest CADR and the best sensor array of the four, and it is still the one we tell readers to skip, because a machine that sells UV-C and ionisation as purification stages fails a veto no score can rescue. That is the point of scoring in this order: the safety questions get answered before the spec sheet gets a chance to impress you.
Practical shortlist: buy the 4 Compact for a small bedroom, the AP4 Lite or AP4 for a typical Indian living room or master bedroom, and step outside this range altogether if you need to cover more than about 240 sq.ft at 5 air changes per hour. Run your own room through the buying checklist and Find an Air Purifier before you commit.
References
All sources mi.com/in. Accessed August 2026.
Product pages, mi.com/in
- Mi Air Purifier 4 official product page, Xiaomi India ↗
- Mi Air Purifier 4 Lite official product page, Xiaomi India ↗
- Mijia Smart Air Purifier 4 Compact official product page, Xiaomi India ↗
- Mijia Smart Air Purifier 6 official product page, Xiaomi India ↗
Related posts on indoorair.guide
- Air Purifier Buying Checklist for Indian Homes
- HEPA 13 vs HEPA 14: Which Filter Do You Actually Need?
- ACH Calculator
Independent, India-focused IAQ resource. Not affiliated with Xiaomi or any manufacturer. Verify specifications before purchase.
All references collated on the Reference Papers page.
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