# What are API key leaks? > API key leaks expose your cloud infrastructure, payment systems, and user data. Learn what causes them, how to detect them, and how to prevent them. Canonical: https://www.phishclean.com/blog/what-are-api-key-leaks Last updated: 2026-08-13 February 24, 2026 · 8 min read By [PhishClean Research Team](https://www.phishclean.com/about) - browser security guidance based on phishing analysis, defensive research, and product work. API keys are the passwords of the modern web. When they leak, attackers get direct access to your cloud infrastructure, payment systems, databases, and user data. Here's everything you need to know about API key leaks — and how to stop them. ## What is an API key? An API key is a secret string that identifies and authenticates an application when it communicates with a service. Think of it like a password, but for software instead of people. When your app needs to send emails through SendGrid, charge a customer through Stripe, or store files in AWS S3, it uses an API key to prove it has permission. API keys come in many formats: # AWS Access Key AKIAIOSFODNN7EXAMPLE # Stripe Secret Key sk_live_51HG4e2CjPEFe8sN3vYdK... # GitHub Personal Access Token ghp_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx # SendGrid API Key SG.xxxxxxxxxxxxxxxxxxxxxx.yyyyyyyyyyyyyy Each of these strings grants significant access to the associated service. An AWS key can spin up servers, access databases, and read files. A Stripe key can view customer payment data and issue refunds. A GitHub token can read and modify source code. ## How do API keys leak? API key leaks happen more often than most developers realize. Here are the most common ways keys end up exposed: ### 1. Committed to Git repositories The most common leak vector. A developer hardcodes an API key during local development, then accidentally commits and pushes it to a public GitHub repository. Automated scanners monitor GitHub in real time — exposed keys are typically discovered by attackers within minutes. GitHub reports that over 100 million secrets were leaked in public repositories in the past year alone. Automated bots scan every new commit within seconds of it being pushed. ### 2. Exposed in client-side JavaScript When API keys are bundled into frontend JavaScript — through environment variable misuse, build tool misconfiguration, or simple mistakes — they become visible to anyone who views the page source. This is especially dangerous because the keys are exposed to every visitor, not just attackers who find them through code scanning. ### 3. Included in documentation or Stack Overflow answers Developers sometimes paste real API keys into documentation, tutorials, or Stack Overflow answers when showing code examples. Even if the key is "for testing only," attackers don't distinguish between test keys and production keys — they try everything. ### 4. Logged in error messages Applications that log full request/response bodies may inadvertently capture API keys in log files. If those logs are accessible — through a misconfigured log dashboard, leaked log file, or error tracking service — the keys are exposed. ### 5. Embedded in mobile app binaries API keys hardcoded in mobile apps can be extracted through reverse engineering. Tools like `strings`, `apktool`, and various decompilers make this straightforward. ## What happens when an API key leaks The consequences depend on the key type and the permissions it grants: - **AWS keys:** Attackers spin up cryptocurrency miners on your account, access S3 buckets containing user data, or delete infrastructure. Bills can reach tens of thousands of dollars within hours. - **Stripe keys:** Attackers can view customer payment information, issue unauthorized refunds, or create fraudulent charges. - **Database credentials:** Direct access to your database means full data exfiltration — user records, passwords, personal information, financial data. - **Email service keys (SendGrid, Mailgun):** Attackers send phishing emails from your domain, damaging your sender reputation and potentially targeting your own customers. - **GitHub tokens:** Attackers read private repositories (potentially finding more secrets), modify source code, or inject backdoors. ## How to prevent API key leaks ### Use environment variables Never hardcode API keys in source code. Store them in environment variables and load them at runtime. Use `.env` files for local development and ensure `.env` is in your `.gitignore`. ### Use a secrets manager For production environments, use a dedicated secrets manager like AWS Secrets Manager, HashiCorp Vault, or Doppler. These services provide encryption, access control, audit logging, and automatic rotation. ### Implement least-privilege keys Create API keys with the minimum permissions needed. If a key only needs to read data, don't give it write access. If it only needs access to one S3 bucket, don't give it access to all buckets. This limits the damage if a key is compromised. ### Rotate keys regularly Set up automatic key rotation on a schedule. If a key leaks, regular rotation limits the window of exposure. Most cloud providers support automated rotation through their secrets management tools. ### Scan for leaks proactively Use tools that detect leaked secrets before they reach production: - **Pre-commit hooks:** Tools like `detect-secrets` or `gitleaks` scan your code before it's committed. - **CI/CD scanning:** Run secret detection in your build pipeline to catch anything that slips through pre-commit hooks. - **Browser-level detection:** [PhishClean's secret leak scanner](https://www.phishclean.com/features/secret-leak-scanner) detects exposed API keys on any web page you visit — catching leaks in documentation, code playgrounds, and misconfigured applications. ## How PhishClean helps PhishClean's [secret leak scanner](https://www.phishclean.com/features/secret-leak-scanner) runs in your browser, checking every page you visit for exposed API keys and credentials. It matches against 30+ known secret patterns — AWS keys, Stripe keys, GitHub tokens, database connection strings, and more. This gives you an extra layer of protection that other tools don't cover: - Detects keys exposed in web pages, documentation, and code playgrounds - Catches [leaked JWT tokens](https://www.phishclean.com/features/jwt-token-leak-detection) that could grant session access - Identifies [phishing pages](https://www.phishclean.com/threats/phishing-attacks) that may be harvesting credentials - Runs 100% locally — your browsing data is never sent to us ## Related reading - [Secret Leak Scanner How PhishClean detects exposed secrets in your browser](https://www.phishclean.com/features/secret-leak-scanner) - [localStorage token security Why storing JWTs in localStorage creates XSS risk](https://www.phishclean.com/blog/localstorage-token-security-risks) - [Formjacking attacks Injected scripts that steal form data from legitimate sites](https://www.phishclean.com/threats/formjacking-attacks) - [SSL stripping attacks How HTTPS gets silently downgraded on public WiFi](https://www.phishclean.com/threats/ssl-stripping-attacks) - [Hidden iframe attacks Invisible iframes that capture credentials and mine crypto](https://www.phishclean.com/threats/hidden-iframe-attacks) - [How to check if a website is safe 7 quick checks before you enter any credentials](https://www.phishclean.com/blog/how-to-check-if-website-is-safe) ## Detect API key leaks in your browser PhishClean scans every page for exposed secrets — locally, in real time. No page source is uploaded for detection. [Install PhishClean](https://www.phishclean.com/#install) Last updated: 13 August 2026 ## Share this guide If this helped, share it with someone who would benefit from it, or subscribe for new browser-security guides from PhishClean. Share on X Share on LinkedIn Get practical phishing and browser-safety articles in your inbox. No salesy drip, just new guides and product updates when they are worth sending.