Solve Supported Captchas Through a Simple API
Fast, developer-friendly captcha recognition with API tokens, usage quotas, flexible plans, and production-ready documentation. Built for authorized automation and testing workflows.
# one request is the whole integration
POST /api/solve
X-API-Token: ••••••••••••••••
Content-Type: application/json
→ Solving…
✓ 200 OK
{
"success": true,
"answer": "12",
"tier_used": "pixelocr",
"duration_ms": 132,
"remaining_solves": "49"
}API Demo
Five languages away from your first solve
The same request in every language — paste your token, send the image, read the answer. Copy a working sample and try it against the live service right now.
curl -X POST https://api.captchaapi.space/api/solve \
-H "X-API-Token: YOUR_API_TOKEN" \
-H "Content-Type: application/json" \
-d '{"image":"<base64>","tier":"auto"}'Response — every field explained
- success
- Whether the captcha was solved. Failed solves are refunded to your quota.
- answer
- The solved value — the numeric result of the equation in the image.
- tier_used
- Which engine produced the answer: pixelocr, pixel or ocrspace.
- duration_ms
- Server-side processing time for this solve.
- remaining_solves
- Your remaining quota after this request.
- pixel_chars
- The exact characters the local engine read (pixelocr tiers).
Captcha Types
Supported formats today — more on the roadmap
We only list support for what the backend actually solves. Math image captchas run on every tier right now; other challenge types are on the roadmap.
Math Image CAPTCHA
Equations rendered as images — "5 + 7 = ?" style. Send base64, a data URL or an image URL and get the numeric answer back.
More challenge types
reCAPTCHA, hCaptcha, Cloudflare Turnstile, GeeTest and 8 more formats are on the roadmap — currently not supported.
Features
Everything an API product needs
Developer First
One simple REST API with predictable JSON responses. Send an image, read the answer — no SDKs required.
Multiple Solver Tiers
Choose auto, pixelocr, pixel or ocrspace per request. The auto tier races engines in parallel and returns the first answer.
Usage Based Plans
Captcha quotas combined with validity periods. Failed solves are refunded automatically — you never pay for errors.
Secure Tokens
API authentication via a secure X-API-Token header. Tokens carry their own quota, plan and validity.
Real-Time Usage
Check remaining quota, plan status and solve history at any time through the status and logs endpoints.
Automatic Error Handling
Clear HTTP status codes and actionable error messages for every failure mode — with quota refunds on failed solves.
API Documentation
Complete endpoint reference, request schemas, error guides and copy-ready examples for eight languages.
Free Trial
Test the API before purchasing — sign up with email verification and start solving on a free trial instantly.
How it works
Three steps. That is the whole integration.
Create an account
Sign up with email verification (OTP). No card required — your free trial starts immediately.
Get your API token
Your token is issued at signup and carries the trial quota. It is all you need to authenticate requests.
POST and read the answer
Send the captcha image as base64 to POST /api/solve with your token. Receive the answer in milliseconds.
Developer Integration
Three input modes, one response shape
POST raw base64, a data URL or let the server fetch an image URL for you. Every solve endpoint returns the same clean response object.
Base64 or data-URL image in the image field.
{"image":"data:image/png;base64,iVBOR...","tier":"auto"}Explicit endpoint for raw base64 payloads.
{"data":"iVBORw0KGgoAAAANSUhEUg...","tier":"pixelocr"}Server-side fetch — private networks are blocked.
{"url":"https://example.com/captcha.png","tier":"ocrspace"}Performance
Measured, not marketing
Numbers below come from the solver benchmark suite shipped with the backend — measured on reference hardware, not invented for the landing page.
~130 ms
Local PixelOCR solve
Median benchmark after the v2.2.0 optimization pass (7.3× faster).
4
Solver tiers
auto, pixelocr, pixel and ocrspace — selectable per request.
2×
Parallel race in auto
Local and cloud engines race; the first correct answer wins.
0
Charged failures
Quota is reserved atomically and refunded on failed solves.
Pricing
Pay for solves, not for seats
Live plan list straight from the service — plans are managed by the admin and always current. Quota never expires mid-plan.
Security
Secure by construction
Token authentication on every solve, strict request validation, SSRF protection on URL fetches, and atomic quota reservation with automatic refunds.
HTTPS + token auth
Every request authenticated with your X-API-Token.
SSRF protection
Private-network addresses are blocked on /api/solve/url.
Request limits
5 MB image cap and strict JSON validation on input.
Atomic quota
Reserve-then-solve with refund on every failure.
Documentation
Reference-grade docs, from quick start to error codes
FAQ
Questions, answered
What is Captcha Solver API?
A developer-friendly REST service for programmatic captcha recognition. You send a supported captcha challenge — today, math-equation images — and receive the solved answer over HTTPS, metered against your plan quota.
How does the free trial work?
Create an account with email verification and a trial quota is issued to your API token instantly — no card required. Track remaining solves from the dashboard or the status endpoint, and upgrade any time via WhatsApp.
Are failed solves charged?
No. Quota is reserved atomically before a solve and refunded automatically when a solve fails, so your quota only decreases for successful answers.
How do I authenticate?
Every solve request carries your token in the X-API-Token header. Create one free account, copy the token from the dashboard, and you are ready.
What happens when my quota ends?
Solves start returning a quota error (HTTP 429). Top up via WhatsApp or upgrade to a bigger plan — your token stays the same.
Which captcha formats are supported?
Math image captchas (base64, data URL or image URL inputs) are live today across all solver tiers. Other challenge formats are on the roadmap — see the Captcha Types page for the full list.
Start solving in under a minute
Create a free account, grab your API token and make your first solve. Upgrade any time — quota never expires mid-plan and failed solves are always refunded.
Free trial includes quota for 50 solves across 7 days