Best free AI tools for stock research

Every existing list of “free AI tools for stock research” was written by someone who spent twenty minutes on each tool’s pricing page. The pieces are pricing-table reviews dressed up as practitioner guides — “has a free tier” treated as the same as “useful at the free tier”, trials counted as free access, the institutional terminals padded in to look comprehensive.

This post does something different. I took each tool to its actual free tier, ran a real research task on it, and wrote down what it returned. The verdict is per task, not per tool — because no one uses one tool for everything, and the question isn’t which AI is best overall but which one belongs at which stage of a research session.

The list is sequenced in that order. First pass on a new name, then verified fundamentals, then document analysis, then alternative data, then a verification layer, then sceptical reasoning, then the data terminal. Used together, these seven cover most of what a retail investor needs before they place a trade — and they cost nothing.

The seven: Perplexity Finance, FinChat, Gemini, Quiver Quantitative, StockAnalysis.com, Claude, and Koyfin.

One rule before the list#

Free tier means permanent free access. A 7-day trial is not a free tool, and any product whose “free” experience is a clock counting down to a paywall does not appear here. Several of the tools below have paid tiers that are better; the question this post answers is what you can do without paying.

1. Perplexity Finance — first pass on a new name#

Use it when: You’ve heard about a company and want a structured briefing (financials, recent earnings, what analysts are saying) before committing time to deeper research.

Why it earns its place: The free tier of Perplexity Finance is the single most capable opening-phase research tool on this list for US equities. Live stock pages, an earnings hub with sourced transcripts and filings, a natural-language screener, price and chart comparisons, consensus analyst estimates. No prompt engineering, no setup. For the first thirty minutes on a new US name, nothing else at free tier comes close.

What the free tier actually includes: Live US stock pages, earnings hub with documents (transcripts, filings), natural-language screener for US and Indian equities, price and chart comparisons, consensus analyst estimates, throttled Deep Research sessions.

I ran the same earnings query on two stocks I follow — BMNR (a smaller US company) and META — and got two completely different tools.

On BMNR, the Earnings Transcript tab showed “Loading…” and never populated. The query returned fifteen secondary sources — Yahoo Finance summaries, news aggregator paraphrases — with no named analysts and no direct quotes from the calls. Perplexity ended its response by suggesting I try Seeking Alpha Premium for transcript access.

On META, the same query returned named analyst Q&A from Morgan Stanley, Goldman Sachs and JPMorgan, with specific Zuckerberg quotes and a cross-call synthesis identifying a recurring evasion pattern in how management answered questions about margin trajectory.

Top: BMNR. Bottom: META. Same tool, same prompt.

Two qualitatively different research experiences. The structured Finance tab depends entirely on whether Quartr — the transcript data partner — has parsed the company. For larger companies it has; for smaller names, including US ones rather than just UK or AIM stocks, you fall back to a web search summary.

Where it falls short: If your watchlist skews to smaller names, Perplexity Finance at free tier is excellent for the household names and approximately useless for everything else.

2. FinChat — verified fundamentals#

Use it when: You want to interrogate the financials of a specific company (revenue trajectory, margin history, earnings cadence) without reading the 10-K yourself, and without an AI inventing the numbers.

Why it earns its place: FinChat’s data is sourced from S&P Market Intelligence — the same database that powers Bloomberg, per FinChat’s own documentation — not scraped from web summaries. When it cites a revenue figure, the citation is verifiable. That distinction matters: general-purpose AI is willing to confidently produce a plausible-looking revenue number that’s wrong by ten per cent. FinChat sources its numbers and shows you where they come from.

What the free tier actually includes: 10 AI Copilot prompts per month, global stock coverage (not US-only), 5 years of annual financial data, 6 quarters of quarterly data, limited earnings call access, financial dashboards and charts.

You can also connect it to your broker — the list of supported brokers is extensive, which is a nice touch for a free tier.

The 10-prompt monthly limit sounds generous until you actually use it. A real fundamentals session — revenue, margins, free cash flow, capex, segments — burns three or four prompts before you’ve answered the first real question. Two companies a month is what the free tier covers before you’re rationing prompts. The data depth is the second constraint: five years of annual data is enough for a trend line, but six quarters of quarterly data is not enough to see a cycle in anything cyclical, seasonal, or post-IPO.

Where it falls short: Ten prompts go faster than you expect. Run one thorough multi-part session on a company and you’ve spent a third of your monthly allowance.

3. Gemini — document-heavy analysis#

Use it when: You have a long PDF (annual report, earnings release, risk factors section) and you want to interrogate it directly rather than skim it.

Why it earns its place: Gemini’s free tier handles file uploads and long documents better than any other free general-purpose AI. ChatGPT free can’t really take a full annual report; Claude free has tighter document limits. Gemini’s free tier will accept a 10-K, hold the context, and answer questions against the actual text — and the daily allowance of thirty prompts plus five Deep Research reports a month is materially more generous than ChatGPT free’s.

What the free tier actually includes: File upload, 30 prompts/day, 5 Deep Research reports/month, web access.

Gemini summarises well and challenges poorly. Ask it to “analyse this annual report” and you’ll get a polished version of how management framed the year. The fix is in the prompt: don’t ask Gemini to assess, ask it to find. “List every risk factor in section 1A that management spends less than a sentence on” or “Find every place the words ‘one-off’ or ‘non-recurring’ appear and quote the surrounding paragraph” gets you something specific to push back on, rather than a tidied-up version of the company’s own story.

The other failure mode is confident-sounding numerical error — Gemini will sometimes paraphrase a financial figure that’s close enough to look right and wrong enough to mislead. Verify any number against the source document.

Where it falls short: If you ask Gemini for a balanced view, you’ll get the company’s version of balance. Make the prompt adversarial or accept the marketing.

4. Quiver Quantitative — alternative data signals#

Use it when: You want signals that don’t come from the company’s own filings: what Congress members are trading, what insiders are doing, what hedge funds are building or selling, where lobbying money is going.

Why it earns its place: Quiver Quantitative’s free tier includes the actual alternative datasets that hedge funds pay for — congressional trading, insider transactions, government contract awards, lobbying spend, institutional holdings, ETF flows. This is not AI inference from news. It’s parsed from public disclosures. No equivalent free source exists for this category of data, and that’s the entire reason it sits on the list.

What the free tier actually includes: Congressional trading tracker, insider transaction data, government contract awards, lobbying spend, hedge fund holdings, ETF flows. All sourced from public disclosures. Backtesting and real-time alerts are paid.

It supplies the signal; you do the interpretation. A congressional buy disclosed in March might be a January trade — the STOCK Act window is 30–45 days, and Senate disclosures often lag further. Insider selling has a dozen benign explanations: 10b5-1 plans, tax on vesting shares, divorce. A spike in lobbying spend can be defensive or offensive. The platform gives you the raw disclosure data, not the reading of it.

The most-watched page in recent years has probably been Nancy Pelosi’s trading history. Following her trades became a retail investor trend — she consistently outperformed the market, and the theory that she had access to material non-public information through her Congressional position gained enough traction to get mainstream media coverage. Whether you believe that or not, the STOCK Act data is public, and this is where you’d look.

Where it falls short: The free tier has no alerts and no backtesting — you find out about a congressional trade when you visit the site, not when it happens. If you want to act on these signals rather than just see them, you’ll need a paid plan.

5. StockAnalysis.com — the verification layer#

Use it when: You want to check whether the financial figure an AI just gave you is correct — without an account, without a prompt limit, without another AI in the middle.

Why it earns its place: StockAnalysis.com isn’t an AI tool in the generative sense. It’s a clean fundamentals database with AI-enhanced screening, free forever, with no login required. It earns its place on a list of AI research tools because it solves the problem that AI research tools create: you need a place to verify what the AI just told you, and most of the obvious verification options (Yahoo Finance, broker apps) are either ad-cluttered or thin on international coverage. StockAnalysis covers more than 130,000 stocks globally, including the international names Perplexity Finance ignores.

What the free tier actually includes: Full financial statements, ratios, historical data, no-login stock screener, IPO calendar, market news digest, ETF data. Ad-supported, free forever.

The AI component is on the screening and data presentation side, not natural-language Q&A. You can’t paste in a company name and ask “why is the operating margin declining” — you have to look at the data yourself. That’s a feature for this use case. The tool’s job here is to be wrong-proof, not to do the thinking. If a generative tool tells you Company X’s revenue grew 18% last year and you want to confirm it, StockAnalysis is two clicks away.

Where it falls short: It gives you the data, not the analysis. You’re using it to verify outputs, not generate them — and you need both, from different tools.

6. Claude — structured sceptical reasoning#

Use it when: You have a view on a stock and you want to stress-test it. Bear case, what-would-change-my-mind, the questions you haven’t asked.

Why it earns its place: Claude’s free tier includes web search, but every search eats into the daily usage limit and the results come back as a list of pages, not the structured financial data you’d get from Perplexity Finance. For the specific job of structured adversarial reasoning, though, Claude is the most controllable free tool available. It handles multi-part structured prompts reliably and tends toward explicit uncertainty rather than the false-confident summarising that Gemini drifts into. If you want the AI to argue back, Claude is the one that will.

What the free tier actually includes: Claude Sonnet, web search (counts against the daily limit), limited file upload, reasonable daily message limits.

This is where the Prompt Stack earns its keep. The free Claude tier on its own is a general assistant. The same tier with a four-part structured prompt — ROLE (act as a sceptical analyst, not a cheerleader), FILTER (here are the observable facts), RISK (name the timing, downside, and what would invalidate the view), VERDICT (one action, with a confidence level) — turns into a structured adversarial reasoner. Paste in your thesis in three sentences, paste in the actual financials from StockAnalysis or FinChat, and ask Claude to argue the bear case against your own framing. You’ll get something usable. Ask the same question without the structure and you’ll get a five-paragraph “on the one hand, on the other hand” essay.

The catch is that Claude doesn’t know what you don’t tell it. Output quality is entirely determined by the inputs — paste in inference instead of numbers and you’ll get inference back, dressed up as analysis.

Where it falls short: Claude’s free tier is a reasoning engine, not a research engine. You have to bring all the facts; it applies the logic to them.

7. Koyfin — data terminal for international coverage#

Use it when: You want a Bloomberg-style data terminal (charts, fundamental metrics, macro overlays, custom watchlists), and your watchlist isn’t all US household names.

Why it earns its place: Koyfin does the thing Perplexity Finance can’t — international coverage. UK and European stocks have proper data pages, with fundamentals, charts, and screening that work the same way they do for US names. For a retail investor whose portfolio includes anything outside the S&P 500, this is the difference between a working tool and a tool that pretends Europe doesn’t exist.

What the free tier actually includes: 2 years of historical financials, stock and ETF data, fundamental metrics, charting, 2 watchlists, 2 custom screens, limited macro dashboards.

The honest limit is data depth. Two years of history is a snapshot, not a pattern — you need at least five years to read a revenue trajectory, margin history, or cycle behaviour. Koyfin knows this, which is why they position the free tier as a demonstration, not a working environment. Paid starts around $39/month, which is reasonable for what you get if you’re researching more than a handful of names. The 2 watchlists and 2 screens cap is the other constraint — for someone tracking five sectors and a dozen names, the free tier gets cramped fast.

Where it falls short: Two years of history is enough for a snapshot but not a pattern. At free, Koyfin shows you what the platform can do, not what you can do with it. Worth noting: I hit network errors trying to create a free account, which suggests the signup experience isn’t well-maintained — not a great first impression for a tool positioning its free tier as a demo.

Where the list stops#

These seven cover the early-to-middle stages of a research session — first pass, fundamentals, document analysis, alternative data, verification, sceptical reasoning, data terminal. They don’t cover everything. Live options chain data has no genuinely free tier; broker apps are still the answer there. Structured coverage of AIM and the broader UK market is patchy across the entire list — Perplexity Finance ignores it, Koyfin partially covers it, FinChat does best but burns prompts fast. Real-time alerts are paid everywhere.

The pre-trade reasoning stage — the hour between deciding a stock is interesting and placing the order — is where this list ends. Five questions to ask AI before buying any stock picks up there, with the prompts I run before any trade goes on.

What didn’t make the list#

ChatGPT free. 10 messages per 5 hours, no Deep Research. A tool that rate-limits you to ten messages over an afternoon — not enough for a single thorough research session — is not a working tool here. It appears on most other lists because the brand is familiar, not because the free tier is useful.

Danelfin. The free tier is the “top 10 stocks to buy” newsletter — a marketing funnel for the paid scoring product. It delivers Danelfin’s conclusions, not the data to form your own. That’s a stock-picker subscription, not a research tool.

Zen Ratings. WallStreetZen’s own product, recommended at the top of WallStreetZen’s own “best AI tools” lists. The free tier is described by the parent site as “limited stock research” without specifying what that limit is. Conflict of interest aside, “limited” without a definition fails the free-tier-honesty test this post is built around.

Prospero.ai. Claims 27% better returns than the S&P 500. Doesn’t publish audited results or methodology. Delivers signals rather than enabling research.

Most of the tools that didn’t make this list have a paid tier that promises to beat the market. None of them publishes audited returns. The tools above were picked because they help you do your own research — not because they promise to do it for you.

These are the seven I’d use. Once you’ve hit the free-tier limits on two or three of them, you’ll know which one is worth paying for — and by then, you’ll have run enough real sessions to make that call yourself.