- Fast answer: Alpha Vantage says its premium U.S. market-data product provides consolidated SIP coverage, alongside fundamentals and more than 100 APIs in one upgrade path. Alpaca is a strong no-cost starting point for real-time U.S. equity data through IEX, while FMP fits low-frequency historical or fundamental research.
- Important correction: Polygon.io is now Massive and offers a free Stocks Basic plan. Databento provides $125 in time-limited credits, not a permanent message allowance. Marketstack has an ongoing 100-request-per-month free plan with no contract or payment required.
- Decision rule: Choose by feed coverage, freshness, redistribution rights and request pattern—not by the word “free” alone.
Run the stock-data task you actually need
A provider comparison is useful only when it leads to a result with a clear market, timestamp, source and adjustment policy. Start with one of these bounded tasks, then use the comparison below to decide which free or paid entitlement can support it.
Resolve the security before accepting the price
Provide a symbol such as AAPL and request a trade, quote or snapshot. The result should identify exactly what the number represents.
- Input: symbol, market or exchange, price type and optional session.
- Return: canonical symbol, security name, price, currency, venue, session, event time, retrieval time and source.
- Boundary: label IEX, SIP, delayed and end-of-day data explicitly; never present one as another.
Request five years with adjustment evidence
A backtest needs more than a price series. Request the coverage window, adjustment method and corporate-action context together.
- Input: symbol, five-year window, daily frequency and adjustment requirement.
- Return: OHLCV, currency, exchange, timezone, splits, dividends, coverage dates, source and retrieval time.
- Boundary: state raw versus adjusted prices and flag incomplete delisted-symbol or corporate-action coverage.
Which free stock API offers real-time data without a credit card?
Alpaca provides free real-time U.S. equity data from the IEX exchange. “Real-time” does not always mean the consolidated U.S. market: Alpaca's free IEX feed represents one venue, whereas SIP coverage is delayed or paid. For entitled consolidated SIP coverage, the client evaluation points to Alpha Vantage's premium U.S. market-data product rather than its 25-request public free key.
Alpha Vantage Premium is the client-tested choice for entitled consolidated U.S. SIP coverage, broad fundamentals and more than 100 APIs. This capability is separate from the public free key.
View Alpha Vantage in QVeris Alpha Vantage official documentation ↗
Alpaca Basic is a strong free starting point for live U.S. equities through IEX. It is useful when single-venue coverage is sufficient, but it is not the consolidated SIP market.
Alpha Vantage is easy to call from Python and spans more than 100 APIs. The standard public free service is limited to 25 requests per day.
View Alpha Vantage in QVeris Alpha Vantage official documentation ↗
FMP Basic lists 250 calls per day with EOD historical and company-reference data, making it practical for low-frequency fundamental research.
Marketstack Free provides an ongoing 100 requests per month, EOD data and one year of history without a contract or payment requirement.
View Marketstack in QVeris Marketstack official documentation ↗
Massive Stocks Basic offers a free low-rate historical/EOD path, while Databento provides a time-limited $125 credit for institutional-data evaluation.
View Massive in QVeris Massive official documentation ↗
View Databento in QVeris Databento official documentation ↗
Learning the response schema and authentication flow.
Building a notebook, classroom project or low-frequency prototype.
Measuring real request volume before choosing a paid plan.
Comparing data quality with reproducible sample queries.
Consolidated real-time coverage across every exchange.
Display, redistribution or commercial product rights.
An SLA, production support or stable plan limits.
Complete history, corporate actions and inactive symbols.
What “Free Stock API” Means in 2026
Search results often mix permanent free tiers, time-limited credits, sandboxes and paid products with free documentation. Those models are not interchangeable. A useful comparison must identify what continues after signup, which datasets are included and what happens when the quota is exhausted.
- Permanent free tier: A recurring allowance with no fixed expiry, such as Alpha Vantage's 25 requests per day, Marketstack's 100 requests per month or FMP's 250 calls per day. Alpha Vantage's current support page also states that it offers unlimited daily requests for verified open-source or educational projects; applicants should confirm eligibility before relying on that allowance.
- Free feed with narrower coverage: Alpaca's Basic data access includes real-time IEX but not the full consolidated SIP feed. A feed can be live and still represent only part of the market.
- Signup credit: Databento gives new accounts $125 in credits that expire after six months. That is valuable for evaluation, but it is not a permanent free message quota.
- Sandbox or delayed access: Some plans expose sample symbols, end-of-day bars or delayed consolidated data. They are useful for integration tests, not a substitute for a licensed production feed.
7 Best Free Stock APIs Compared (Updated August 2026)
The table separates recurring free allowances from signup credits and checks the dimensions that change an implementation decision: quota, feed freshness, payment requirement, permitted use and streaming access. The same seven providers are evaluated under the same versioned standard and listed alphabetically.
| API | Free Tier Type | Free Allowance | Rate Limit | Data Freshness | Credit Card | Commercial Use | WebSocket (Free) |
|---|---|---|---|---|---|---|---|
| Alpaca | Genuinely Free | No hard daily cap | Account / endpoint limits | Real-time IEX; SIP delayed 15 min | Not required (data only) | Verify display / redistribution | Yes |
| Alpha Vantage Official documentation | Limited Free | 25 req/day | Daily quota | EOD on Free; delayed and real-time U.S. data are premium | Not required | Verify license | No |
| Databento | Signup Credit | $125; expires in 6 months | Usage / subscription based | Historical with credit; live by plan | Required | License / dataset dependent | With live subscription |
| Financial Modeling Prep Official documentation | Limited Free | 250 req/day | Daily quota | EOD; up to 5 years | Not required | Individual use | No |
| Marketstack | Limited Free | 100 req/month | Monthly quota | End-of-day | Not required | Paid plans list commercial use | No |
| Massive (Polygon.io) | Limited Free | Stocks Basic $0 | 5 calls/min | Historical / EOD on Basic | Not required to start | Individual plan; verify rights | No on Basic |
| SiftingIO | Limited Free | 10,000 calls/month per market | 60 req/min | Aggregated derived reference; refreshed | Not required | Not on free; paid from $79/month | Yes (1 connection, 5 symbols) |
Limits can change without notice. Recheck the linked official plan and licensing pages before production procurement.
Summary judgment: Alpha Vantage documents broad API coverage and says its premium U.S. market-data product provides consolidated SIP coverage, with an accessible paid upgrade path. Alpaca is compelling for no-cost real-time IEX access; FMP is strong for free EOD fundamentals; Massive is again relevant because Stocks Basic is free. Databento belongs in the “free credit” category, not the permanent free-tier category. Paid capabilities are discussed separately from the free-tier assessment.
Best Free Stock API by Use Case
There is no universal winner. These recommendations map the most common long-tail searches to the constraint that actually decides the answer.
Real-time U.S. stock quotes
Choose Alpha Vantage for entitled consolidated SIP coverage; this is a premium capability and is separate from the 25-request free key. Choose Alpaca when free real-time IEX coverage is sufficient and a single-venue feed meets the application's needs.
Python prototype
Alpha Vantage and FMP both have simple REST responses and broad Python examples. Pick Alpha Vantage for breadth and FMP for SEC-sourced fundamentals.
Historical data and backtesting
Alpha Vantage supports split- and dividend-adjusted prices, long historical series and historical listing-status queries; full output and adjusted daily data are premium capabilities. Use Massive or FMP for redundancy, and confirm lookback depth, delisted-symbol coverage and adjustment rules before trusting a backtest.
Free WebSocket stock API
Alpaca is the clearest streaming candidate in the seven-provider test. Compare the actual feed, symbol subscriptions, connection limits and reconnect behavior—not only REST quotas.
No credit card required
Marketstack, Alpha Vantage and FMP can be started without payment. Databento is different: its $125 credit is applied before charges, but payment information is required at registration.
Commercial or customer-facing use
Do not choose from quota alone. Ask the provider about display, non-display, derived data and redistribution rights. An API key working in production does not prove that customer-facing use is licensed.
Provider Deep Dive: Strengths, Limits and Hidden Trade-offs
The quota is only one part of the decision. Coverage, adjustment methodology, market-feed scope and licensing usually become more important as a prototype moves toward production.
Alpha Vantage — broad endpoints and a licensed upgrade path
Alpha Vantage covers stocks, ETFs, forex, crypto, macro indicators, fundamentals and technical indicators across more than 100 APIs. Its current support page states that the public free service is capped at 25 requests per day, with unlimited daily requests for verified open-source or educational projects. Alpha Vantage also states that it is a Nasdaq-licensed data provider and that its entitled premium U.S. market-data product provides consolidated SIP coverage with millisecond-level timestamps. Here, millisecond-level describes timestamp precision, not API network latency. This premium market-data entitlement is separate from the 25-request free key, so developers should confirm the applicable feed, timestamp semantics and usage rights before launch. For a plan-level breakdown, see Alpha Vantage Pricing: Complete Guide.
Alpaca — real-time IEX is useful, but it is not SIP
Alpaca's free market-data offering includes live IEX data and 15-minute-delayed SIP data. IEX is a single exchange and Alpaca's documentation describes it as suitable for testing or cases where precise consolidated pricing is not the priority. This distinction matters for spreads, liquidity, intraday highs and any system that assumes a national best bid and offer.
Financial Modeling Prep — useful EOD fundamentals with licensing boundaries
FMP Basic lists 250 calls per day, end-of-day access and a useful collection of company profile and reference endpoints. That makes it a practical fit for low-frequency screening, company research and daily portfolio reports. The free plan should not be treated as a blanket commercial license: customer display and redistribution can require a separate agreement, and a production team should verify the exact datasets and lookback available to its account.
Marketstack — a small permanent allowance for occasional EOD work
Marketstack's free plan lists 100 requests per month, end-of-day access and one year of history. It is useful for validating authentication, response fields and an occasional daily snapshot, but the monthly budget is too small for a regularly refreshed dashboard. Treat commercial rights as plan-specific and confirm them before using the data in a customer-facing product.
Massive — Polygon's free tier is back in the comparison
Polygon.io now operates as Massive, and its current stock documentation lists Stocks Basic at $0 alongside paid Starter, Developer and Advanced plans. Basic is useful for reference data and historical/EOD exploration at a low request rate; live trades, quotes and full streaming coverage remain plan-dependent. Older comparisons that describe Polygon as paid-only are now stale.
Databento — excellent evaluation credit, not free forever
New Databento accounts receive $125 in credits shared by the team and expiring after six months. The credit can fund historical requests or offset a first subscription month. Payment information is required, and live data depends on subscription and exchange licensing. Databento is a strong institutional-data evaluation option, but it should not be presented as a permanent free real-time tier.
SiftingIO — free multi-market REST and WebSocket in one account
SiftingIO covers U.S. stocks, forex, crypto, commodities and DEX through one REST API, with a per-market free tier of 10,000 calls a month, 60 requests a minute, one month of history, and a free WebSocket connection limited to five symbol subscriptions—no card required. In our August 18, 2026 tests, quote, trade and OHLCV endpoints responded promptly with current values for stocks, forex and crypto. Consistent with SiftingIO's attestation, these are aggregated derived reference values rather than an exchange raw feed. The free tier is explicitly non-commercial, and its one-month historical depth is the main constraint to check before a backtest; paid plans start at $79/month.
Free Stock API Limits That Actually Matter
A daily quota rarely tells you whether an API will work. Model the full request path and the rights attached to the returned data.
1. Requests per decision, not requests per symbol
A single stock-research answer may require a quote, daily bars, fundamentals, earnings, news and peer data. A 20-symbol scan at six endpoints per symbol consumes 120 calls before retries. Batch endpoints, caching and precomputed snapshots can change the economics more than a headline rate limit.
2. Feed coverage: IEX, SIP or one exchange
“Real-time” describes latency, not completeness. A live single-venue feed can differ from the consolidated market in last price, volume, bid/ask and intraday range. Document the feed name in every downstream record so analysts know what they are comparing.
3. Historical depth and adjustment policy
Backtests need more than OHLCV. Verify split and dividend adjustments, delisted securities, ticker changes, survivorship bias, time zones and whether the free plan truncates history. Two APIs can return valid but incompatible series for the same ticker.
4. Display, non-display and redistribution rights
Personal analysis, automated trading, a public dashboard and reselling derived signals can fall under different licenses. Before launch, record the provider, dataset, entitlement, user type and permitted output. Do not infer commercial rights from the existence of a free API key.
5. Failure behavior and quota recovery
Test HTTP 429 handling, retry headers, daily reset time, partial responses, stale-cache behavior and WebSocket reconnection. A production agent should surface the data timestamp and provider error instead of silently turning missing values into a confident answer.
How to Choose a Free Stock API for Your Project
Match the provider to the job the application performs today, then define the trigger that would force a different feed or paid plan.
Start with Alpha Vantage, FMP or Marketstack. Prioritize batch coverage, adjusted daily bars and fundamentals over streaming.
Start with Alpaca IEX. Upgrade to Alpha Vantage when consolidated coverage or customer display rights become necessary.
Alpha Vantage says its entry-level service covers 20+ markets. Confirm which exchanges and symbols are included before designing the schema.
Compare Alpha Vantage and FMP Basic. Require documented adjustments, delisted symbols and enough lookback for the intended regime.
Use Databento's $125 credit to test schemas, venues and download size. Set a budget cap and remember that the credit expires after six months.
Shortlist by license first. Obtain written confirmation for display, redistribution and derived outputs before optimizing price or request volume.
Practical rule: Build a one-day request budget before integrating: symbols × endpoints × refreshes × retries. If the result uses more than 60% of the free allowance in normal traffic, design caching, batching and an upgrade path before launch.
When a Free Stock API Stops Being the Right Choice
The upgrade trigger should be an engineering or licensing requirement, not a calendar date. A free plan can remain adequate for a daily research notebook and be unsuitable on day one for a customer-facing quote product.
Upgrade when one of these conditions becomes true
- Normal traffic regularly consumes more than 60–70% of the quota, leaving no room for retries or market events.
- A delayed or single-venue feed changes the product's answer, alert or execution decision.
- The product needs display, redistribution, derived-data or professional-user rights absent from the free plan.
- Historical depth, corporate actions or delisted-symbol coverage is insufficient for reproducible research.
- The provider offers no SLA or support path for a failure that would affect paying users.
Compare total cost, not the first paid-plan price
At the August 3, 2026 review, entry points differed substantially: Alpha Vantage premium plans started at $49.99/month, Marketstack Basic at about $9.99/month, FMP Starter from $22/month when billed annually, Massive Stocks Starter at $29/month, while Databento combined subscriptions, usage charges and exchange licensing. These are dated snapshots, not permanent prices. Not all paid plans are equivalent: the lowest sticker price may omit the feed, history or usage rights your application needs.
Reproducible free stock API benchmark protocol
Plan pages describe entitlements; they do not prove how an endpoint behaves in a real workflow. For this evaluation, applicable response checks were run twice to confirm response shape and compare returned values. That repetition improves confidence in the observation, but it does not establish a latency SLA, long-term reliability ranking or public free entitlement. Teams repeating the comparison should use the same bounded test and retain the raw responses.
Use the same symbols, endpoint category, observation window, region, account tier, client location and retry policy.
Store request time, HTTP status, provider timestamp, feed name, response headers, payload hash, latency and the exact terms page used.
Record 401, 403 and 429 responses, Retry-After behavior, reset windows, partial payloads and whether reconnects lose subscriptions.
Separate verified plan facts from measured results. Include test date, environment and limitations so another developer can reproduce or challenge the comparison.
Download the machine-readable August 3, 2026 provider evidence snapshot. It records source URLs and verification status; it does not claim unrun performance measurements.
Free Stock API Python Example: Test Before You Integrate
The safest first script does more than print a price. It records the provider, response time, returned timestamp and rate-limit behavior. The example below uses Alpha Vantage's documented demo key so the request can be reproduced without exposing a private credential.
import time
import requests
url = "https://www.alphavantage.co/query"
params = {
"function": "TIME_SERIES_DAILY",
"symbol": "IBM",
"apikey": "demo",
}
started = time.perf_counter()
response = requests.get(url, params=params, timeout=15)
latency_ms = round((time.perf_counter() - started) * 1000)
response.raise_for_status()
payload = response.json()
print({
"provider": "Alpha Vantage",
"status": response.status_code,
"latency_ms": latency_ms,
"last_refreshed": payload.get("Meta Data", {}).get("3. Last Refreshed"),
"rate_limit_note": payload.get("Note"),
})Do not label the result “live” until the response timestamp, exchange/feed and delay match the plan documentation.
Count every quote, bar, fundamental, news and retry request. A free allowance that supports one endpoint may fail the complete product workflow.
Persist provider, endpoint, feed, symbol, currency, event time and retrieval time. This makes provider comparisons and later migrations auditable.
Free Stock API FAQ
Test the task before choosing the API contract
Run a bounded quote or adjusted-history request first. Inspect the returned market, currency, timestamp, source and entitlement labels, then use the seven-provider comparison above to choose the plan that can reproduce that result in production.