What one sleeve costs on each site
OS1st lists the FS6 at $24.99 for a single sleeve and $39.99 for a pair (os1st.com, 13 Sep 2026). Koprez lists the Foot Sleeve at $39.99 for one, shown struck through from $79.99 with a "50% OFF" badge (koprez.com, 13 Sep 2026). That is a $15.00 gap on the smallest quantity either brand sells, and it is the single most useful number on this page. Our own single sleeve is $29.99, which puts OS1st $5.00 under us on the same row.
The harder question is what "one" buys you, and the two brands answer it very differently. OS1st answers in text on the product page: "Pairs come with two (2) sleeves per package. Singles are only available in Black." Koprez does not. The product title "Koprez® Foot Sleeve" is singular, the description gives no count, and the only place a count appears is inside the quantity selector, where the first option reads "1 Sleeve $39.99 Each" (koprez.com, 13 Sep 2026).
OS1st is not perfectly clean on this either, because its product header shows only $24.99 until you select the Pair option (os1st.com, 13 Sep 2026). The difference is that OS1st resolves the ambiguity with a sentence and Koprez resolves it with a dropdown.
The four regular prices Koprez publishes for the same sleeve
The quantity tiers on the main Koprez product page read, verbatim: "1 Sleeve $39.99 Each", "2 Sleeves +Free Shipping $10 OFF $34.99 Each", "4 Sleeves Most Popular $40 OFF $29.99 Each", "6 Sleeves Best Value $90 OFF $24.99 Each" (koprez.com, 13 Sep 2026). Buying six sleeves is what it takes for a Koprez sleeve to reach the price OS1st charges for one.
| Where it appears | Price for one sleeve | What the page says |
|---|---|---|
| koprez.com/products/foot-sleeve | $39.99 | struck through from $79.99, badge "50% OFF" |
| koprez.com/products/foot-sleeve, 6 sleeve tier | $24.99 each | "6 Sleeves Best Value $90 OFF $24.99 Each" |
| koprez.com/products/foot-sleeve-pair | $69.99 | tier table says "1 Pair $10 OFF $69.99 Each" while the same page headlines $79.99 for two |
| koprez.com homepage tile | $79.99 | no discount badge, so the struck-through price is shown as the live one |
| offers.koprez.com/foot-sleeve-deg-bogo | $19.99 each | "Buy 1, get 1 free, 2 sleeves at $19.99 each. Regular price $79.99 per sleeve." |
| offers.koprez.com/Plantar-Fasciitis-Sleeves-EM | $39.99 | "Save $40", under a banner reading "SPRING SALE: FREE Shipping + 50% OFF!", read in September |
Count the prices Koprez calls regular across its own properties and you get four: $39.99, $79.99, $69.99 and $19.99, the highest of them four times the lowest. OS1st publishes two prices, $24.99 and $39.99, and they are the price of two different things.
There is one row in all of this that Koprez wins outright, and it is worth a cent. The cheapest published Koprez price for two sleeves is $39.98 (offers.koprez.com/foot-sleeve-deg-bogo, 13 Sep 2026), against $39.99 for the OS1st pair the same day. Koprez is one cent cheaper for two, if you land on that particular offer page, while two sleeves at the $34.99 tier on the main product page come to $69.98, which is $29.99 more than the OS1st pair for the same count.
The rows, both brands, plus ours
| Koprez (koprez.com, 13 Sep 2026) | OS1st FS6 (os1st.com, 13 Sep 2026) | KnitPair (13 Sep 2026) | |
|---|---|---|---|
| One sleeve | $39.99 | $24.99 | $29.99 |
| Cheapest published price for two sleeves | $39.98 on offers.koprez.com, $69.98 on koprez.com | $39.99 | $37.99 |
| Fibre percentages | not published | 76% Micro-Nylon, 24% LYCRA Spandex | not published |
| Sizes | 6 | 6 | 3 |
| Size chart as readable text | image only | image only | yes, cm and in |
| Compression, mmHg | not published | not published | not published |
| Returns window | 30 days | 30 days | 100 days |
| Sleeve count stated before checkout | only in the quantity selector | yes | yes |
The fibre row, which OS1st wins outright
OS1st publishes "24% LYCRA® Spandex, 76% Micro-Nylon" on the FS6 page (os1st.com, 13 Sep 2026), and it is the only brand on that table, ours included, that publishes fibre percentages at all. We do not publish ours. Koprez's material description reads "Premium nylon-spandex. Hypoallergenic, breathable, chemical-free. Durable comfort for daily wear." (koprez.com, 13 Sep 2026), which names two fibres and no proportions, so you cannot tell whether the sleeve is mostly nylon with a little elastane or something closer to half and half, and those two garments behave differently on the foot.
The row everybody loses
Compression is the specification a compression sleeve is named after, and not one of these brands publishes an mmHg figure. The string does not appear on any of the eleven Koprez pages read on 13 September 2026, it is not on the FS6 page the same day, it is not published by One Compress, which is measured on these same rows in Koprez vs One Compress vs KnitPair, and it is not published by us.
That matters for how you read any claim about pressure. Koprez Meta ad id 1412433000108659, started 10 March 2026 and still active on 13 September 2026, describes "Biolateral Circular Compression that drives blood flow deep into damaged tissue for real healing", and no published pressure figure sits behind that phrase on any Koprez page we read. None of these brands gives you the number that would make a sleeve a dosed device rather than a garment with a fit you can feel.
Both size charts are images. The Koprez size guide at koprez.com/pages/fs-size-guide contains a heading and one image file, with an empty alt attribute and zero table elements on the page (checked 13 Sep 2026). The OS1st chart is the image file OS1st-SizeCharts_FS6_Bracing-26_Q1.png (os1st.com, same day). On a phone, next to a tape measure, both make you pinch and zoom.
Where Koprez genuinely beats OS1st
Sizes are a draw, and a draw is worth stating because it is the row people assume Koprez wins. Koprez publishes six, S through 3XL (koprez.com, 13 Sep 2026). OS1st publishes six, X-Small through XX-Large (os1st.com, 13 Sep 2026). Ours is three.
Colour for a single sleeve is a genuine Koprez win. Koprez publishes three colours, and OS1st publishes three as well but states that singles come in black only (both sites, 13 Sep 2026), so a buyer who wants one sleeve in anything other than black has one option here rather than two.
| Koprez (koprez.com) | OS1st FS6 (os1st.com) | |
|---|---|---|
| Free US shipping over | $60.00 | $65.00 |
| Otherwise US shipping costs | $4.99 | $6.95 |
| Stated US delivery | "Up to 5 Business Days" on the shipping policy, "1-5 business days" in the FAQ | 3 to 7 business days |
| Returns window | 30 days from receipt | 30 days |
| Colours for a single sleeve | 3 | black only |
Read from koprez.com/pages/returns-and-exchange on 13 September 2026, the Koprez 30 day trial starts the day the parcel is received, returns must be shipped within 14 days of instructions, there is no restocking fee, and refunds take 5 to 10 business days, while a size exchange is a paid extra bought at checkout for $9.99. OS1st publishes a 30 day window at os1st.com/pages/returns-and-exchanges, and no exchange product was recorded in the OS1st pages read.
Koprez's advertising footprint is the one measurable difference here. The public ad libraries on 13 September 2026 showed 546 active US Meta ads on Koprez page 104789644587334, plus roughly 300 Google ads under the advertiser name "Mandala Group LLC", with the newest creatives started 12 September 2026. That is a support and marketing footprint OS1st is not shown to match on this page, because the ad sweep covered Koprez and One Compress only and produced no figure for OS1st either way.
The Black Friday sale that started in March
Meta ad id 1034503363082045 is titled "Black Friday Buy 1 Get 1 FREE + 30-Day Money-Back Guarantee" and opens "BUY 1, GET 1 FREE for Black Friday + 30-Day Money-Back Guarantee!". It started on 30 March 2026 and was still running on 13 September 2026, which is five and a half months of continuous Black Friday in a public library anyone can open.
It is not an isolated creative. Of 90 active Koprez US ads sampled on 13 September 2026, 80 carried a buy one get one free offer, about 89 percent, and the offer page at offers.koprez.com/Plantar-Fasciitis-Sleeves-EM was running a banner reading "SPRING SALE: FREE Shipping + 50% OFF!" when it was read in September. A discount that never ends is a price, so the useful way to read the Koprez $39.99 is as the price rather than as half of $79.99.
The FS6 page carried $24.99 and $39.99 with no strikethrough price, no countdown and no seasonal banner (os1st.com, 13 Sep 2026).
The ratings, both numbers, both sources
Koprez publishes "4.7/5 Based on reviews from 500K+ customers" and "(10,242 Reviews)" on its homepage and product page, with sub-scores "Resullts 4.7/5 | Easy to Take 4.9/5 | Quality 4.7/5 | Value for Money 4.6/5", the typo theirs (koprez.com, 13 Sep 2026). Its claimed Trustpilot profile showed 4.3 from 765 reviews on the same day, 82 percent five star and 9 percent one star, marked "Claimed profile • September 2022" and carrying a paid Trustpilot subscription label (trustpilot.com/review/koprez.com, 13 Sep 2026).
Both numbers are real, they come from two sources with two different moderation regimes, and 765 third party reviews against a claimed 500,000 customers is a ratio worth holding in mind. The customer count is not stable either: Koprez ads say "200,000+", koprez.com says "500,000+", and offers.koprez.com/Plantar-Fasciitis-Sleeves-EM says "Over 100,000 Real Satisfied Customers", all live on 13 September 2026, the largest of the three five times the smallest. All three were live on 13 September 2026, and all three are open for you to check.
No third-party review profile for OS1st was read on 13 September 2026.
Who should buy OS1st, who should buy Koprez, and who should wait
OS1st wins most of the rows on this page. It is cheaper for one sleeve by $15.00 against Koprez and by $5.00 against ours, it is the only one of the four publishing a fibre percentage split, 24% LYCRA® Spandex and 76% Micro-Nylon (os1st.com, 13 September 2026), it states in text how many sleeves are in a package, and it publishes one price per item instead of four. That is the finding, and printing it is the reason to trust the rest of the page.
Buy the OS1st FS6 if you want one sleeve and you want to know what it is made of. At $24.99 it is the cheapest single in this comparison (os1st.com, 13 Sep 2026), and its page tells you it is 76% Micro-Nylon and 24% LYCRA Spandex, which sounds like a low bar until you read the other product pages in the category. For a first sleeve, bought to find out whether you like wearing one at all, this is the straightforward answer and the cheap one.
Buy Koprez if you want a single sleeve in a colour, or if you want a bought size exchange. Three colours available as singles, a published $9.99 "Perfect Fit Guarantee™" add-on at checkout, free US shipping from $60 with a stated $4.99 flat rate below that, and a returns page that spells out the 14 day return window, the absence of a restocking fee and the 5 to 10 business day refund (koprez.com, 13 Sep 2026). Go in knowing that the price you pay is the price rather than a 50 percent saving, and that the same brand sells two sleeves for $39.98 on one of its own pages and $69.98 on another, so if you are buying Koprez, buy from the page with the lower number on it.
Buy nothing yet if what you actually wanted was a compression figure. None of these brands publishes one, so if you have been told to wear a specific pressure, no page in this comparison can tell you whether any of these garments delivers it. The thing to do is ask whoever told you, rather than pick whichever sleeve has the loudest copy.