Best ETF comparison tools, tested on four capabilities
Almost every ETF comparison tool does the same thing: two funds side by side on cost, size and past return. Those are the three numbers least likely to separate them. The capability that decides the comparison is whether the tool can tell you how much of the same thing the two funds already hold, and among the 100 largest US equity ETFs, 9.9% of pairs are more than half the same fund.
Four capabilities, in the order they matter: does it quantify holdings overlap; does it compare the underlying companies' growth, profitability and valuation rather than the funds' returns; does it place each figure against the fund's own history; and only then, does it lay out cost, size and liquidity side by side.
No tool here does all four. Stock Analysis has the cleanest free side-by-side and does not measure overlap; ETF Research Center measures overlap better than we do and adds sector drift, which we do not publish.
Updated 24 August 2026
What to compare, and what a tool must show you
- What each fund holds, and how much of it is the same.
- How concentrated each one is — the top-ten weight.
- What the companies inside are worth, against peers and against the fund's own past.
- Cost and liquidity last — a bar to clear, not a way to choose.
What a comparison tool has to do
A side-by-side table of two funds is easy to build and easy to find, which is why every tool has one. It answers the questions that are already answered everywhere. A comparison earns its place by answering the ones that are not:
- How much do the two funds already share?
- As a percentage of each fund's weight, in both directions. Without it you cannot tell whether you are choosing between two options or looking at one position twice. How overlap is measured.
- What are the companies inside actually like?
- Growth, profitability and valuation aggregated from the holdings. Two funds with the same label, the same fee and similar past returns can hold companies with very different economics.
- Where does each figure sit against the fund's own past?
- Comparing two funds' multiples tells you which is dearer today. Comparing each against its own history tells you whether either has changed — which a like-for-like comparison cannot show, because both may have moved together.
- Cost, size and liquidity
- Necessary, and last. Among funds that differ on the first three, a few basis points of fee rarely decides anything.
One live pair from each relationship, measured by weight across every holding.
| Pair | Shared weight | First in second | Second in first | What that is |
|---|---|---|---|---|
| IVV & VOO | 97% | 99.7% | 99.9% | Effectively the same fund |
| IVV & QQQ | 53.5% | 53.5% | 94.5% | One sits inside the other |
| QQQ & VGT | 52.1% | 55.4% | 77.1% | Less alike than they look |
| VTI & VXUS | 1.3% | 5.1% | 5.5% | Potential diversifiers |
The tools, capability by capability
Checked on each provider's own site · monthly price in USD where published · ETFdb publishes no price.
| Tool | Price /mo | Side by side cost, size, returns | Quantifies holdings overlap | Underlying fundamentals | Vs own history |
|---|---|---|---|---|---|
| Stock Analysis | $9.99 | Yes | No | Bare figures | No |
| ETF Research Center | $29 | Overlap-led | By weight | Vs category | No |
| ETF Copilotthis site | $20 | Yes | Both ways | Aggregated | Yes |
| ETFdb / VettaFi | Not published | Yes | Not quantified | Category avg | No |
| Yahoo Finance | $7.95 | Two tabs | No | Returns only | No |
| Koyfin | $39 | Yes | Not found | Paid | Paid |
Which one to use, by what you are comparing
- Two funds you suspect are near-duplicates
- ETF Research Center or ETF Copilot — both quantify overlap by weight in each direction. Nothing else on this page returns a number for it.
- Two funds with similar labels and different fees
- ETF Copilot's compare pages — the underlying fundamentals are aggregated from holdings and shown against each fund's own history, which is where two similar-looking funds usually differ.
- A quick free look at cost, size and returns
- Stock Analysis — the cleanest free side-by-side, no account. It will not tell you what the two funds share.
- Category context for a fund you do not know
- ETFdb / VettaFi — category averages and letter grades alongside the raw figures, free.
What is the best ETF comparison tool?
It depends on which of the four capabilities you need. For a free side-by-side of cost, size and returns, Stock Analysis. For how much two funds share, ETF Research Center or ETF Copilot. For the fundamentals of the companies inside, measured against each fund's own history, ETF Copilot is the only one here that publishes it.
Can I compare two ETFs for free?
Yes, for the basics. Stock Analysis, ETFdb and Yahoo Finance all put two funds side by side on cost, size and past return without an account. Overlap between the two is free on ETF Research Center. The underlying fundamentals of what each fund holds are the part that is rarely free anywhere.
What should I compare, if not the fee?
Holdings overlap first, then concentration, then the growth, profitability and valuation of the companies inside, then cost. How to compare two ETFs works through the order with an example.
How was this compared?
Each tool was opened on its own site, logged out, and given two large US equity ETFs. A tool counts as quantifying overlap only if it returns a number for how much the two funds share; as comparing fundamentals only if the figures describe the underlying companies rather than the funds' returns. Prices are the advertised monthly rate on the provider's own pricing page. ETFdb publishes no price and blocks automated access, so its row was read by hand.
Compare two funds on what they hold →
About this comparison. ETF Copilot is one of the tools listed here, and it appears where its capabilities place it — its own row states plainly what it does not do. Every other tool is an independent product. No listing is paid for, there are no affiliate links, and links to other providers are ordinary links.
ETF Copilot reports data factually. Nothing on this page is investment advice, a recommendation, or a forecast of returns. It describes how to read fund data, not what to do with it. Third-party capabilities were checked on each provider's own site on 24 August 2026.