Capital.com vs Interactive Brokers API
The same fields from the Capital.com record and the Interactive Brokers record, side by side. No winner is picked: which one suits you depends on what you are building.
Independent and unofficialNewest check
Risk warning: CFDs and spread bets are complex instruments and come with a high risk of losing money rapidly due to leverage. You can lose money on these products, and each provider publishes its own loss figure under FCA rules. You should consider whether you understand how they work and whether you can afford to take the high risk of losing your money. Automated and API trading can amplify losses through bugs, connectivity failures and runaway orders.
What the two records show
Differences you can see in the records themselves. These are counts of what this site holds, not a verdict on either API.
- Capital.com is recorded as a broker with an API of its own. Interactive Brokers is recorded as a broker with an API of its own.
- This site documents 36 endpoints for Capital.com and 23 endpoints for Interactive Brokers. That counts what has been documented here, not what each API offers.
- This site has decoded 24 error codes for Capital.com and 511 error codes for Interactive Brokers.
- The limits register holds 1 limit record for Capital.com and 6 limit records for Interactive Brokers. Each limit record carries its own scope.
- The Capital.com record holds a demo claim, verified at its source. The Interactive Brokers record holds a demo claim, verified at its source. The wording of each is in the Demo row below.
- A quickstart is built here for both.
Capital.com and Interactive Brokers, field by field
| Field | Capital.com | Interactive Brokers |
|---|---|---|
| Kind | Broker with its own API | Broker with its own API |
| API family | REST, WebSocket | TWS API (TCP socket), REST (Client Portal Web API), WebSocket |
| How you get access | Enable 2FA, then Settings > API integrations > Generate new key, with a custom key password.Capital.com Public APIchecked | No key: run TWS or IB Gateway (TWS API) or the Client Portal Gateway and log in via browser (Web API).IBKR TWS API documentation, the IB Gatewaychecked |
| Who can use it | Any Capital.com account (demo or live) with 2FA enabled. Regional limits not published.Capital.com Public APIchecked | Open, funded IBKR Pro account. The Web API supports only IBKR Pro accounts, and the TWS API lists a funded and opened IBKR Pro account among its requirements.IBKR Web API v1.0 documentation, requirements and limitationschecked |
| Demo | Yes: separate demo base URL.Capital.com Public APIchecked | Partial: paper trading accounts are supported and the Web API is logged in to with a separate paper username; demo accounts cannot subscribe to data.IBKR Web API documentation, using a paper accountchecked |
| Authentication | POST /session with the X-CAP-API-KEY header plus login credentials returns CST and X-SECURITY-TOKEN, sent on later calls. The session expires after 10 minutes of inactivity.Capital.com Public APIchecked | TWS API: local socket to a TWS or IB Gateway the user has logged in to by hand. Web API: Client Portal Gateway with a browser login on the same machine; the Web API also lists OAuth 1.0a, OAuth 2.0 and SSO, and IBKR's older use cases page gives OAuth as the route for institutional clients.IBKR TWS API documentation, the IB Gatewaychecked |
| Streaming | WebSocket wss://api-streaming-capital.backend-capital.com/connect, maximum of 40 epics per subscription; the session lasts 10 minutes and is kept alive with ping.Capital.com Public APIchecked | TWS API is event driven over the socket. The Web API websocket is at /v1/api/ws (wss://localhost:5000/v1/api/ws through the gateway): the number of market data subscriptions depends on the account's market data lines, 100 by default, a market data stream ends after 15 minutes unless it is requested again, and at most 5 historical data requests run at once.IBKR Web API v1.0 documentation, websockets introductionchecked |
| History depth | Candles: max 1,000 per request (default 10), MINUTE to WEEK. Activity history: max 1 day per from/to call. Transactions default to last 10 minutes.Capital.com API referencechecked | Bars of 30 seconds or less are not available beyond six months, and expired futures not beyond two years from expiry. IBKR's current TWS API documentation, read on 12 Oct 2026, counts three pacing violations for bars of 30 seconds or less: an identical historical data request within 15 seconds, six or more requests for the same contract, exchange and tick type within two seconds, and more than 60 requests in any ten minute period, with a BID_ASK request counted twice. The Web API endpoint /iserver/marketdata/history has its own published pacing of 10 requests a second or 50 a minute. Executions: since midnight by default, up to 7 days in TWS if its Trade Log setting is changed, and the current day only in IB Gateway.IBKR TWS API documentation, unavailable historical datachecked |
| Limits |
|
|
| Endpoints documented here | 36 | 23 |
| Error codes decoded here | 24 | 511 |
| Official documentation | open-api.capital.com | interactivebrokers.com |
Go deeper on each side
Capital.com
- Capital.com API page, the full record
- Capital.com API quickstart, credentials to a first call
- Capital.com API limits, in the table above
- Capital.com API error codes, each with its fix
- Capital.com API endpoints, each with its source
- Get your Capital.com trade history into a spreadsheet
- Capital.com API with Python
Interactive Brokers
- Interactive Brokers API page, the full record
- Interactive Brokers API quickstart, credentials to a first call
- Interactive Brokers API limits, in the table above
- Interactive Brokers API error codes, each with its fix
- Interactive Brokers API endpoints, each with its source
- Get your Interactive Brokers trade history into a spreadsheet
- IBKR API without TWS: headless IB Gateway options
- The three Interactive Brokers REST front doors compared
- Interactive Brokers MCP servers, compared
All comparisons. New to this? Getting started with API trading.