How we compare

Where the specs come from

Every spec on a product page (part number, dimensions, weight, load capacity, drawers, material, weather rating) is a claim we recorded with its source: the page it was read from, how it was read, and the date. The product page shows the source next to each value, so you can check it in one click.

Sources rank in this order:

1. The brand's own material: its product page, spec sheet or product feed.
2. A store's listing of that exact part number, when the brand doesn't publish the figure.
3. Anything else, such as a search result or a figure worked out from the source's own numbers. These values are marked with an asterisk.

Within a rank, a page read directly beats an archived copy of it. When a store blocks automated reading, we read the copy the Internet Archive keeps instead, and the source says "archived".

Of the 1,317 spec values shown on the site right now, 73% come from the brand, 26% from a store and 1% from other sources. Another 1% are carried over from the original catalogue and haven't been re-checked yet. Those are labelled not re-verified wherever they appear.

When sources disagree

The highest-ranked source wins, and among equals the newest reading wins. A value carried over from before we kept sources ranks below everything, so any checked reading replaces it.

When two good sources disagree by more than measuring noise (half an inch or 3% on a dimension, 5% on a weight), we look at both and mark the wrong one rejected, with the reason. Rejected claims are kept rather than deleted, so the next check doesn't pick the same wrong number up again. 191 claims have been rejected so far.

A few conventions make products comparable:

• Dimensions are length × width × height in inches. Length is the longer side of the footprint, because brands disagree about which side they call length. Height is measured with any handle folded down.
• Load capacity is what the product is rated to carry. A lid's standing load is a different figure and isn't recorded.
• Material uses a short shared vocabulary (polypropylene, ABS, steel and so on), so a brand's marketing name for its plastic doesn't hide that it's the same plastic.

Confirmed, inferred, unconfirmed

Every product carries a confidence label. It's computed from its sources, never typed in by hand:

• confirmed (267 products): the part number and every shown spec were read from the brand's or a store's own page, spec sheet or feed, or an archived copy.
• inferred (57): read the same way, but at least one value rests on a search result or a figure worked out from the source's numbers, or the product has no part number to pin it to.
• unconfirmed (12): at least one value hasn't been re-checked since the catalogue began. The product page says which.

Prices

Prices are re-checked every week. Each price shows the date it was seen and the store it was seen at. The headline price is the cheapest store that has the product in stock. If no store has a price, we show the brand's list price, labelled as such. A price we haven't been able to re-check reads "recorded <date>, not re-checked since", never as current.

Some large stores refuse automated price checks. For those, we look the part number up by hand and record the price the store's own listing shows. When we can't do that, the store is listed without a price rather than with a guessed one.

Size tiers

Brands name sizes differently: one brand's "large" is another's "medium". The size filter (compact, medium, large, XL) places each product by its size within its own line. We use the brand's own size word when the name has one. Otherwise we rank the product by outside volume against its line-mates, or an editor places it. Tiers are for narrowing a list, not a claim that two boxes are the same size, so the measured dimensions are always shown next to them.

What stacks with what

Most systems only lock onto their own brand. Where two systems do stack, natively or through an adapter, we say so on both lines' pages and on every product page, and name the source for the claim: the brand's own statement where there is one. A compatibility claim without a source isn't published.

Discontinued products

Products a brand no longer sells new stay in the catalogue, because people buy them used and need to know what they stack with. They're kept out of every comparison, listed under legacy & discontinued, and each one names what replaced it. 6 products are listed there now. 17 entries have been removed outright as duplicates or mistakes, each with a recorded reason.

How the site makes money

Some "buy" links are affiliate links: if you buy through one, the store pays Modular Toolbox a commission at no cost to you. Those links say so right next to the button. Affiliate status never decides what we list, the order things appear in, or which store a price comes from. The headline price is the cheapest in-stock store, whether or not we earn from it. No brand or store pays for placement.

What we don't do

• No scores or "best" picks. A single score hides whose priorities set the weights. We show the numbers and the sources, and you decide.
• No hands-on testing. Specs are the brand's or store's published figures. A rated load is the brand's rating, not something we measured.
• US market only. Part numbers, prices and availability are for US stores.
• No guessing. A value nobody has published is left blank, not estimated.

What the terms mean

Weather rating (IP54, IP65…)

An IP code from the IEC 60529 standard. The first digit is dust (5 = dust-protected, 6 = dust-tight); the second is water (4 = splashing, 5 = low-pressure jets, 6 = powerful jets, 7 = brief submersion). IP65, the common rating here, means dust-tight and protected from water jets. It doesn't mean the box can sit in water. Where a brand publishes no rating we show none, which doesn't mean the box leaks; it means nobody has claimed otherwise.

Rated load

What the brand says one piece is built to carry. It's per piece, not per stack, and it's the brand's figure, not something we measured. A lid's standing load is a different number and isn't recorded.

Dimensions and outside volume

Outside length × width × height in inches, length being the longer side of the footprint and height with any handle folded. "Outside volume" is just those three multiplied and turned into gallons (231 cubic inches each): a way to compare overall bulk, not how much fits inside.

Size tier

Compact, medium, large or XL within the product's own line, so lineups can be lined up across brands. Two "large" boxes from different brands aren't the same size; the dimensions say how they differ.

Stacks directly / with an adapter

"Directly" means the latches of the two systems lock onto each other as they are. "With an adapter" means a named part sits between them. Each pair is marked confirmed (the brand says so), reported (a hands-on test or reference source says so) or inferred (the evidence points to it but nobody states it).

Confirmed, inferred, unconfirmed

How a product's data was sourced; see above.