The best under sink water filter under $100 is the Waterdrop 10UA. It installs in minutes, connects to your existing faucet, and its filter lasts up to a year (11,000 gallons).
We compared eight top-rated under sink water filters under $100 on Amazon and used only the certifications and specs each brand lists. We don’t test water ourselves, so check your local water report and confirm certifications before you buy.
Every pick here is a direct-connect carbon or ultrafiltration system for city water – not reverse osmosis – so they keep minerals and don’t lower TDS. The main differences are filter life (5,000 to 22,000 gallons), number of stages and whether a dedicated faucet is included. Below are our top picks, a comparison table, detailed reviews, a buying guide and FAQs.
Top 3 Under Sink Water Filters Under $100 at a Glance
Waterdrop 10UA
Waterdrop 15UA
Waterdrop TSA 3-StageUnder Sink Water Filters Under $100 Compared
| Image | Product | Key Specs | Rating | Price |
|---|---|---|---|---|
| 1. Waterdrop 10UA Best Overall | 11,000 gal / 1 year · NSF/ANSI 42 certified | 4.6/5 14,386 reviews | Check Price |
| 2. Waterdrop 15UA Longest-Life Waterdrop | 2-year filter life · Multistage filtration | 4.5/5 8,806 reviews | Check Price |
| 3. Waterdrop TSA 3-Stage Best Multi-Stage | 3 filters, 8-layer filtration · Reduces PFAS & fluoride | 4.4/5 2,667 reviews | Check Price |
 | 4. Waterdrop 10UB with Faucet Best with Dedicated Faucet | Lead-free stainless faucet · 11,000 gal / 1 year | 4.6/5 7,175 reviews | Check Price |
 | 5. ICEPURE WFS5300A Best Long Filter Life | 22,000 gal / 3 years · NSF/ANSI 42 & 372 | 4.5/5 3,419 reviews | Check Price |
 | 6. PUREPLUS Under Sink Filter Best 5-Year Filter | 5-year / 22,000 gal · NSF/ANSI 42 | 4.6/5 1,811 reviews | Check Price |
 | 7. Waterdrop 10UAW-UF Best Ultrafiltration | 0.01 µm UF membrane · 1.33 gpm max | 4.6/5 14,386 reviews | Check Price |
 | 8. AQUA CREST 5KDC Best Budget | 5,000 gal / 12 months · 0.5 micron carbon | 4.5/5 1,393 reviews | Check Price |
1. Waterdrop 10UA – Best Overall
Waterdrop 10UA Under Sink Water Filter System, NSF/ANSI 42 Certified 1 Year
Amazon rating: 4.6/5 from 14,386 reviews
Pros
Cons
The Waterdrop 10UA is the best under sink water filter under $100. It costs about $44, has 4.6 stars from 14,386 reviews and ranks #2 in Under-Sink & Countertop Filtration on Amazon.
It is the simplest way to get filtered water straight from your existing faucet, with no drilling and no extra spout on the sink.
Key features
NSF/ANSI 42 certified. The filter is certified to reduce chlorine taste and odor, and Waterdrop says a larger filtration area gives 20X more dirt adhesion area to reduce clogging.
Three-minute install. Twist-and-lock construction and push-to-connect fittings make installation quick, and filter swaps take seconds. It comes with a 3/8-inch line that connects to standard US 3/8-inch feed valves.
Cheap replacements. Waterdrop says the WD-RF10 replacement filter (ASIN B085G66JTZ) costs under $25.99, which it says saves over 50% on later filter changes.
What it’s like to own
Because it filters the cold line feeding your main faucet, every glass and pot of water from that tap is filtered. Waterdrop lists a 1-year filter life in the product title.
It is designed for municipal tap water and cold water only. Waterdrop says it is not suitable for well water or hot water, so check your supply before buying.
Best for: City-water homes that want filtered water from the main faucet.
May not fit: Well water or anyone who needs TDS reduction.
2. Waterdrop 15UA – Longest-Life Waterdrop
Waterdrop 15UA Under Sink Water Filter System, 24420 Gallons, 2 Years
Amazon rating: 4.5/5 from 8,806 reviews
Pros
Cons
The Waterdrop 15UA is the best long-life pick under $50. Waterdrop rates it for up to 24 months or 24,420 gallons on municipal water, and it has 4.5 stars from 8,806 reviews for about $49.
Key features
Two-year service life. Up to 24 months per filter on city water.
Multistage filtration. Waterdrop says it reduces PFOA/PFOS, lead, chlorine, heavy metals, chemical impurities and sediment.
Clog resistance. The same 20X dirt adhesion area upgrade as the 10UA.
What it’s like to own
The replacement is the WD-RF15 (ASIN B085G78F7R). Waterdrop suggests storing filters sealed in the fridge if you go on vacation.
Like the 10UA, it is for cold municipal water only.
Best for: Homeowners who want fewer filter changes.
May not fit: Well water.
3. Waterdrop TSA 3-Stage – Best Multi-Stage
Waterdrop TSA 8 Layer Under Sink Water Filter System, NSF/ANSI 42 Certified
Amazon rating: 4.4/5 from 2,667 reviews
Pros
Cons
The Waterdrop TSA is the best multi-stage system under $100, with 3 filters and 8 layers of filtration for about $95. It has 4.4 stars from 2,667 reviews.
Key features
8-stage filtration. Waterdrop says it reduces PFAS, PFOA/PFOS, residual chlorine, fluorides, silt, rust and cysts, and its resin reduces fluorides.
IAPMO-certified CT filter. The carbon filter passed IAPMO certification for residual chlorine reduction.
Keeps minerals. It does not reduce TDS and helps retain beneficial minerals.
What it’s like to own
It connects to faucets with 1/2-inch or 3/8-inch female NPT threads. Replacements are the WD-10PP (B0CM8MHWNT), WD-10GC (B0CM8KV1M9) and WD-10CT (B0CM8SDWWD).
Waterdrop notes that flow is lower after full 8-stage filtration. For well water, use a pre-filter.
Best for: Anyone concerned about fluoride or PFAS.
May not fit: Anyone who wants maximum flow.
4. Waterdrop 10UB with Faucet – Best with Dedicated Faucet
Waterdrop 10UB Under Sink Water Filter System with Dedicated Faucet
Amazon rating: 4.6/5 from 7,175 reviews
Pros
Cons
The Waterdrop 10UB is the best under sink filter with a dedicated faucet, at about $58 with 4.6 stars from 7,175 reviews.
Key features
Dedicated faucet. Filtered water comes from its own faucet, leaving your main faucet unfiltered for washing.
IAPMO certified. Certified against NSF/ANSI 42 for chlorine taste and odor and NSF/ANSI 372 for lead-free materials.
Multistage filtration. Waterdrop says it reduces PFOA/PFOS, chlorine, heavy metals and sediment.
What it’s like to own
It uses the same WD-RF10 filter as the 10UA, which Waterdrop prices under $25.99.
A dedicated faucet may need a hole in your sink or countertop. It is for cold municipal water only.
Best for: Anyone who wants a separate drinking-water tap.
May not fit: Sinks with no spare hole.
5. ICEPURE WFS5300A – Best Long Filter Life
Amazon rating: 4.5/5 from 3,419 reviews
Pros
Cons
The ICEPURE Under Sink Water Filter is the best for long filter life under $60. ICEPURE rates it for 3 years or 22,000 gallons, with 4.5 stars from 3,419 reviews for about $54.
Key features
NSF/ANSI 42 and 372. Reduces chlorine taste and odor and is certified lead-free.
2.5 GPM flow. ICEPURE lists a tested full flow rate of 2.5 GPM at 60 PSI.
Plug-and-play install. Under 3 minutes to install and 2 seconds for a filter change.
What it’s like to own
ICEPURE says it retains beneficial minerals while improving taste.
A 3-year filter life keeps maintenance minimal.
Best for: Set-and-forget owners.
May not fit: Anyone needing lead reduction claims.
6. PUREPLUS Under Sink Filter – Best 5-Year Filter
Amazon rating: 4.6/5 from 1,811 reviews
Pros
Cons
The PUREPLUS Under Sink Filter offers the longest rated life here at 5 years or 22,000 gallons, certified by IAPMO, for about $59. It has 4.6 stars from 1,811 reviews.
Key features
NSF/ANSI 42 certified. A 6-in-1 composite filter with 0.5-micron accuracy reduces 99% of chlorine and odor.
2.5 GPM flow. Up to 2.5 GPM at 60 PSI.
Lead-free materials. Certified against NSF/ANSI 372 by IAPMO.
What it’s like to own
PUREPLUS says the average daily cost is under $0.018.
It is for cold water only.
Best for: Lowest long-term cost.
May not fit: Hot water lines.
7. Waterdrop 10UAW-UF – Best Ultrafiltration
Waterdrop 10UAW-UF 0.01 μm Ultra Filtration Under Sink Water Filter System
Amazon rating: 4.6/5 from 14,386 reviews
Pros
Cons
The Waterdrop 10UAW-UF is the best ultrafiltration pick under $100, with a 0.01-micron membrane for about $70. Its 4.6-star rating from 14,386 reviews is shared with the 10UA listing.
Key features
0.01-micron UF membrane. Reduces chlorine, taste, odor and heavy metals.
Lab tested. Third-party tested against NSF/ANSI 372.
Direct connect. Fits faucets with 1/2-inch or 3/8-inch female NPT threads; no faucet included.
What it’s like to own
The replacement is the WD-RF10W-UF (ASIN B08CXFSVMV).
Waterdrop asks you to contact it before purchase if you need a female threaded connector.
Best for: Anyone who wants finer filtration.
May not fit: Faucets with non-standard connections.
8. AQUA CREST 5KDC – Best Budget
AQUA CREST 5KDC Under Sink Water Filter System
Amazon rating: 4.5/5 from 1,393 reviews
Pros
Cons
The AQUA CREST 5KDC is the cheapest pick at about $32, with 4.5 stars from 1,393 reviews.
Key features
Coconut carbon + KDF. 0.5-micron coconut shell carbon and KDF media.
Tested to NSF/ANSI standards. Reduces chlorine, taste and odor and VOCs, per AQUA CREST.
1.5 GPM flow. AQUA CREST says it fills a cup in 3 seconds.
What it’s like to own
The filter lasts 12 months or 5,000 gallons – about 5 cents a day, per AQUA CREST.
It includes braided stainless inlet and outlet hoses and mounting hardware.
Best for: Tightest budgets.
May not fit: Long filter life.
How to Choose an Under Sink Water Filter Under $100
Direct connect or dedicated faucet
Direct-connect systems (Waterdrop 10UA, 15UA, 10UAW-UF, TSA, ICEPURE, PUREPLUS, AQUA CREST) filter the water going to your existing faucet. The Waterdrop 10UB adds a separate drinking faucet, which may need a sink or countertop hole.
Filter life
Filter life ranges from 12 months (AQUA CREST, Waterdrop 10UA) to 2 years (15UA), 3 years (ICEPURE) and 5 years (PUREPLUS). Longer life means lower maintenance, but check replacement prices too.
Certifications
NSF/ANSI 42 covers chlorine taste and odor; NSF/ANSI 372 certifies lead-free materials. Look for these certifications rather than marketing claims alone.
What it removes
Most of these filters target chlorine, taste and odor. The Waterdrop TSA adds fluoride and PFAS reduction claims, and the 10UAW-UF uses a 0.01-micron membrane. None of them lowers TDS.
Water source and connections
Nearly all of these filters are for cold municipal water only. Check your faucet threads (1/2-inch or 3/8-inch female NPT) and feed valve size before ordering.
Flow rate
The ICEPURE and PUREPLUS list 2.5 GPM at 60 PSI; the AQUA CREST lists 1.5 GPM; multi-stage systems like the TSA flow more slowly.
FAQ
What’s the best under sink water filter under $100?
The Waterdrop 10UA, with 4.6 stars from 14,386 reviews at about $44.
Can I install an under sink filter myself?
Yes. Waterdrop and ICEPURE say their systems install in about 3 minutes with push-to-connect fittings.
Do under sink filters work with well water?
Most here are designed for municipal water only. Waterdrop says the TSA needs a pre-filter for well water.
Do these filters reduce fluoride?
The Waterdrop TSA says its resin reduces fluorides. The others don’t claim it.
How often do I change the filter?
From 12 months (AQUA CREST, 10UA) to 5 years (PUREPLUS).
Do under sink filters lower TDS?
No. These are carbon/UF systems; for TDS reduction, consider reverse osmosis.
Final Verdict
The Waterdrop 10UA is the best under sink water filter under $100: it is cheap, easy to install, NSF/ANSI 42 certified and backed by a huge review base.
For fewer filter changes, choose the Waterdrop 15UA (2 years), ICEPURE (3 years) or PUREPLUS (5 years).
For fluoride and PFAS reduction, pick the Waterdrop TSA; for a separate drinking tap, the 10UB; for finer filtration, the 10UAW-UF; and for the lowest price, the AQUA CREST 5KDC.
Quick picks:
- Best overall: Waterdrop 10UA
- Best multi-stage: Waterdrop TSA
- Best with faucet: Waterdrop 10UB
- Longest filter life: PUREPLUS (5 years)
- Best budget: AQUA CREST 5KDC
Related buying guides: Best Under Sink Water Filters Under $200 · Best Under Sink Water Filters Under $300 · Best Water Filter Pitchers Under $50
