Security glass is a must-have accessory for the Xiaomi Redmi 9, especially if your smartphone is equipped with an NFC module. Installation can not only spoil the appearance of the screen, but also block contactless payments. Unlike film, glass requires accuracy: the slightest speck of dust or skew — and the result will be far from ideal.
Many Redmi 9 owners are faced with a dilemma: trust the installation of the masters or risk doing everything yourself. In fact, gluing glass at home is real - the main thing is to know the key nuances, from the choice of material to the leveling technique. NFC-antennas (it is located at the top of the back cover) so as not to block the signal with too thick or metallized glass.
This article is a step-by-step algorithm based on the specifics of the model, a list of tools you need, and common mistakes that make the glass peel off after a week, plus proven life hacks for the perfect result the first time.
Why it’s important to choose the right glass for the Redmi 9 with NFC
Not every security glass is suitable for Xiaomi Redmi 9 with NFC module. The fact is that the antenna is located under the top of the case, and too thick or metalized coating can shield the signal, as a result, the smartphone no longer reads bank cards or tags, although the NFC itself is on.
The optimal glass thickness for this model is 0.2-0.33 mm. thicker options (0.5 mm and higher) can worsen the sensitivity of the fingerprint sensor (if it is built into the screen) and NFC.
- 🔹 Material: Tempered glass with oleophobic coating (repels fat and prints).
- 🔹 Round edges: for Redmi 9s 2.5D-screen fits only glass with rounded edges.
- 🔹 The speaker cutout: must match the hole in the screen, otherwise the sound will be muffled.
- 🔹 Set: the set should be wet and dry wipes, dust collector, sticker for positioning.
Critical: If you use a magnetically fastened case (for example, for wireless charging), metallized glass can conflict with magnets, causing artifacts on the screen.
Xiaomi's official accessories (Mi Protective Glass series) are guaranteed to be compatible, but often more expensive than their counterparts. Budget options from Spigen, Nillkin or AmFilm will also work - the main thing is to check reviews about compatibility with NFC.
Preparing the phone: what to do before installation
Before gluing the glass, Xiaomi Redmi 9 needs to be carefully prepared, neglecting this stage is the main cause of bubbles and dust under the glass. Start by turning off your smartphone: this will eliminate accidental touches of the screen and reduce the risk of static electricity attracting dust.
Follow the algorithm further:
- Remove the cover and film (if any) and wipe the body with a dry microfiber wipe.
- Clean the screen with a wet wipe from the kit (or an alcohol napkin with at least 70% isopropyl alcohol content), moving from center to edges.
- Remove the glue residue (if there was a film before) with tape or a special cleaner. Do not use acetone - it will damage the oleophobic screen covering!
- Check the lighting: Ideally, a bright light at a 45° angle to see even microscopic dust.
⚠️ Warning: Do not clean the screen with household detergents (such as Mr. Proper or glass liquid) and leave a film that worsens the adhesion of the glass.
After cleaning, don’t touch the screen with your hands – even fingerprints can prevent even gluing.If there is a lot of dust in the room, close the windows and use an air humidifier (dust settles faster when high humidity).
Turn off phone |Remove cover and old film |Rub the screen with an alcohol napkin |Remove the residue of glue with scotch |Check the lighting-->
Step-by-step: how to glue glass without bubbles
Now, to the most critical stage, your goal is to perfectly align the glass the first time, because once you stick it, it's almost impossible to move it without consequences.
Step 1: Positioning
Take the glass out of the package, remove the protective film with the adhesive side (only one!). On the Redmi 9 screen, place a positioning sticker (usually included) that will help align the glass in the center. If there is no sticker, use tape, gluing it cross-patched on the screen (remove it carefully).
Step 2. Sticking
Take the glass by the edges and gently place it on the screen starting at the top (where the speaker and the front camera are located). Don't push it, let it lie under its own weight. If the glass falls curve, don't try to move it! Better tear it off and start over.
Step 3: Bubble removal
Once glued, take a plastic card (or a special scraper from the kit) and gently move from center to edges to drive out the air. If there are small bubbles, leave them for 12-24 hours: often they disappear on their own.
Step 4 Final check
Turn on the phone and check:
- 📱 Screen sensitivity (especially around the edges).
- 💳 Work. NFC: Bring your phone to the terminal or tag.
- 🔊 The sound of the speaker (must not be muffled).
- 👆 Fingerprint sensor (if any).
⚠️ Attention: If after installation NFC If it's not working, check if the glass is blocking the antenna at the top of the body, and in some cases, it helps to re-install the glass with a downward displacement of 1-2 mm.
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If the glass is glued to a curve, and it is impossible to tear it off without consequences - heat the screen with a hair dryer (temperature not higher than 40 ° C) and gently tuck the glass with a plastic card. The glue will soften, and you can remove it without traces.
Common Mistakes and How to Avoid Them
Even with a careful installation, many people face problems, and here are the most common mistakes and ways to prevent them:
| Mistake. | Reason. | How to fix it |
|---|---|---|
| Bubbles around the edges | Dust or moisture under glass, uneven pressure | Remove the glass, clean the screen, glue again with the air discharge card |
| The glass peels off in a week. | Low-quality glue or greasy marks on the screen | Use glass with 3D-glue and carefully degrease the screen |
| NFC doesn't work | Glass too thick or metallized | Replace with glass 0.2-0.33 mm thick without metal layer |
| Rainbow divorces on screen | Cheap glass without oleophobic coating | Buying glass marked Oleophobic Coating |
| The fingerprint sensor is not working. | Glass thicker than 0.33 mm or incorrectly installed | Reinstall the glass or choose a model with a cutout under the sensor |
Another common problem is the lens effect, where the glass distorts the image around the edges, which is because the radius of the glass and the screen is not matched. 2.5D-The display is suitable only glass marked Full Cover. 2.5D.
What to do if the glass is cracked?
If there are cracks in the glass, but the screen is intact, don't take it off. It still protects the display from scratches. However, if the cracks interfere with use (for example, touch your finger), carefully remove the glass with a plastic card, clean the screen and paste a new one.
How to check the quality of glass before buying?
How to care for glass so it lasts longer
Even the strongest glass loses its properties over time if it is not properly cared for.
1.Purge.
Use only microfiber wipes and special liquids for screens (for example, Whoosh! or iCloth).
- 🧼 Household detergents (corroding oleophobic coatings).
- 🧻 Paper wipes or toilet paper (scratching).
- 👕 T-shirts or T-shirts (leaves the pile).
2 Storage
If you remove glass (for example, to replace it), store it in the original packaging, sticky side up. Do not put heavy objects on it - even tempered glass can crack from point pressure.
3. Scratching protection
Don’t put your phone in your pocket with keys, coins, or other metal objects. If you wear a Redmi 9 without a cover, avoid contact with hard surfaces (such as tables with a stone countertop).
⚠️ Warning: If there are deep scratches on the glass that cling to the finger, it is better to replace it.
4.NFC verification
Once a month, test the NFC: hold your phone to a payment terminal or a tag, and if the signal gets weaker, the glass may have started to peel off or deform.
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The oleophobic coating of glass wears off over time, and if the screen gets dirty faster, use a remedial (like Liquid Oleophobic Coating) or replace the glass.
What to do if NFC stops working after glass installation
If, after the glass has been glued, NFC-The chip has stopped responding to cards or tags, and the problem may be one of three factors:
- Incompatible glass: too thick or with a metallized layer.
- Incorrect positioning: glass covers the antenna at the top of the body.
- Antenna damage: rare, but possible under high pressure during installation.
How do you diagnose?
Open Settings → Connected Devices → NFC and check if the module is on. If so, the reading doesn't work:
- 📱 Try to bring the phone to the terminal from a different angle (the antenna may be shifted).
- 🔄 Reboot your smartphone – sometimes resetting the module’s temporary data helps.
- 🔍 Take the glass off and check. NFC If it works, it's the glass problem.
If NFC It doesn't work even without glass, it's possible that the antenna has been damaged before (for example, when the phone falls). NFC-module at the service center.
Temporary solution (if the glass is already glued and it is difficult to remove):
Use contactless payments through Google Pay/Samsung Pay -- they're often more stable than a direct card emulation, and you can also attach an external card. NFC-Rear cover tag (sold on AliExpress).
Alternatives to protective glass: when it is not suitable
Not all Xiaomi Redmi 9 owners are comfortable with glass, and in some cases it is better to consider alternatives:
1. Hybrid film.
Thin (0.1–0.15 mm) films with a coating that mimics glass (e.g. Spigen Glas.tR EZ Fit).
- 🔹 Not affected. NFC and print-sensor.
- 🔹 Easy to glue and remove.
- 🔹 Cheaper glass.
Cons: worse protect against blows, scratch faster.
2. Liquid glass
It's applied as a coating to the screen, filling in microcracks, suitable for those who don't want to glue anything.
- 🔹 Not protective against heavy blows.
- 🔹 Requires repeated application every 6-12 months.
- 🔹 Not compatible with some covers (may be washed).
3.Covers with a cut-out under the screen
If you drop your phone a lot, consider cases with a built-in bumper (like UAG Plasma or Spigen Tough Armor) that lift the screen above the surface, reducing the risk of damage when you fall. Minus — do not protect against scratches on the screen itself.
⚠️ Note: If you use wireless charging, make sure that the selected case or glass does not block the signal.Some metallized accessories may heat up or interfere with charging.