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ALTCHA
ALTCHA Solver: Bypass the ALTCHA Proof of Work
ALTCHA hides no picture to read, just a number your computer has to find. CapSkip finds it on your own processor in milliseconds, with no browser to launch, and a single monthly fee covers every challenge you send.
Windows x64·Runs locally, so no CAPTCHA leaves your machine
- No browser, no proxy
- Milliseconds per solve
- Light on hardware
ALTCHAs a month20,000
20.0k250.0k
$24.80stays in your pocketevery month, at this volume
Behind the small ALTCHA box there is no picture and no puzzle, only a math task, so an ALTCHA solver needs processor time rather than eyes. CapSkip supplies that time from the Windows desktop or VPS where you install it: it takes the challenge the site hands out, tries numbers until one fits, and returns the proof the form is waiting for. No browser window opens and nothing travels to a solving farm.
ALTCHA ranks among the easiest work CapSkip takes on. A typical challenge clears in milliseconds, so an ordinary office PC or a small VPS keeps pace with busy form traffic, and each extra core lets another solve run alongside. Because the answer is calculated rather than recognized, accuracy simply is not a question: CapSkip either finds the number or tells you the challenge could not be solved.
Paying by the thousand for a few milliseconds of computing never added up. Metered services (2Captcha, Anti-Captcha and SolveCaptcha among them) still charge for ALTCHA that way. CapSkip is a flat monthly plan priced by device count, from $35 with no setup fee, and it never tallies solves or retries. Connect it through the browser extension for Chrome or Firefox, an official SDK, or the automation tools you already run.
A modest PC is enough. ALTCHA is pure processor work: no browser launches for it and no extra network setup is involved. The PC on your desk or a small VPS handles it next to your other jobs, and a free trial shows how it copes with your own forms. Start the free trial
ALTCHA bypass that runs on processor time alone
Pure CPU work, nothing rendered
ALTCHA never needs a page drawn on screen or a mouse moved. CapSkip solves it as straight computation, so no browser instances pile up in memory and a basic machine copes.
No proxy to rent
The challenge is arithmetic, not a check on where your traffic comes from, so ALTCHA solving runs straight from your own connection. Save that budget for the CAPTCHA types that actually look at your IP.
Milliseconds per challenge
A typical ALTCHA challenge clears in milliseconds on your own processor. There is no upload, no waiting line and no remote worker who has to pick the job up first.
A computed answer, never a guess
Nothing is read or recognized, so there is no accuracy rate. CapSkip either finds the number the challenge asks for or reports plainly that this challenge cannot be solved.
Old and new ALTCHA setups
Sites on the older ALTCHA scheme and sites on the current one are both covered, in the box, checkbox and switch styles. CapSkip works out which setup it was given on its own.
Expired challenges solved again free
ALTCHA challenges go stale quickly, so some get solved twice. On a flat monthly plan, the second or tenth attempt adds nothing, and neither does a record day.
Pick how ALTCHA reaches CapSkip
from capskip import CapSkip
solver = CapSkip(host="127.0.0.1", port=8080)
# Point CapSkip at the endpoint the ALTCHA widget fetches its challenge from,
# or pass challenge_json= if you already hold the document itself.
result = solver.altcha(
url="https://example.com/register",
challenge_url="https://example.com/altcha/challenge",
)
# result["token"] goes straight into the hidden "altcha" form field.
print(result["token"], result["number"])The Python SDK at work: hand CapSkip the address of the site's ALTCHA challenge and get back the answer your form submits.
Extension in Chrome or Firefox
Leave the ALTCHA box to the extension. It hands each challenge over to the desktop app, then lets the widget finish and verify itself, with no code involved.
SDKs for your own scripts
Your PHP or Python scripts, Node.js apps and .NET programs call one ALTCHA method and get back the finished answer, ready to go out with the form.
Tools already set up for 2Captcha
Bots and scripts that send ALTCHA to 2Captcha or Anti-Captcha today can be pointed at CapSkip instead, and their requests are then answered on your own machine.
Up and solving ALTCHA in three steps
-
Install CapSkip on any Windows box
ALTCHA is light work, so a basic Windows computer or a small VPS is plenty. Run the installer, open the app, and the solver is ready to take challenges. Download the installer
-
Activate a plan or the trial
Pick a monthly plan by the number of machines you want solving, or begin on the free trial if you would rather see it work before paying. CapSkip emails you the details to sign in to the app. Compare the plans
-
Send ALTCHA your usual way
Leave ALTCHA to the extension in your browser, call the SDK from your scripts, or switch a tool built for 2Captcha or Anti-Captcha over to CapSkip from the app. Follow the setup guide
Local ALTCHA solving vs a metered service
The same proof of work gets done either way. What changes is where it runs, how long you wait and what each challenge costs you.
| Feature | CapSkip | Per-solve services |
|---|---|---|
| How you pay | A flat monthly plan, solves never counted | A fee on each batch of 1,000 ALTCHA solves |
| Where the work happens | Your own CPU, whether a desktop or a VPS | On a remote server that receives each challenge |
| Time per challenge | Milliseconds, with no upload or waiting line | A trip across the network, then a queue |
| What leaves your machine | Nothing: the challenge and the site stay private | The challenge and the site address go to a third party |
| Expired or repeated challenges | Solved again at no extra cost | Each new attempt is billed as a fresh solve |
| Solving in parallel | As many threads as your cores can carry | Limited by the queue and available workers |
| Getting connected | Extension, SDKs, or your current bots unchanged | Only through their API, with client code to write |
Pricing
Stop paying per solve
Choose your license
Bronze License
$35/ month
Instant license activation
Billed monthly. Cancel from your account whenever you like.
Same features. More machines, more throughput.
Every machine solves as fast as its own CPU and memory allow. More machines run more threads at the same time, so Silver solves twice as many CAPTCHAs at once and Gold three times as many.
- Unlimited solving, no daily cap
- Unlimited threads, speed scales with your hardware
- 90% to 100% recognition accuracy
- Drop-in replacement for the major solving service APIs
- Works with almost any tool, no coding required
- REST API, SDKs and a browser extension
- Free training when a new CAPTCHA type appears
- Runs on your machine, nothing leaves it
Every CAPTCHA type CapSkip solves is on every license. See the coverage band
Just want to try it first?
Start with a free 3-day trial and solve 500 CAPTCHAs of any type on your own targets.
ALTCHA proof of work: why a per-solve bill makes no sense
A proof-of-work CAPTCHA does not test whether you can see. It tests whether your device is willing to spend a moment of computing. When the form loads, the site hands out a math problem with only one way to crack it: try number after number until one fits. A visitor's browser does that quietly while they type, which is why ALTCHA feels invisible to most people and why privacy-minded and self-hosted sites favor it over image grids and third-party trackers.
For automation, that moment of computing is tiny per form but real across thousands of submissions. Per-solve services still price ALTCHA by the thousand, as if someone had to look at it, even though the job is a few milliseconds of processor time. Every challenge that expires before you post it and must be solved again is charged again too. With CapSkip the work runs on hardware you already own, and the monthly fee stays put whether you solve a handful of challenges or a mountain of them.
CapSkip covers ALTCHA the way sites run it today: the older scheme built on the SHA family, and the newer one built on PBKDF2, the setting ALTCHA itself recommends, along with its repeated SHA option. The box, checkbox and switch styles all end in the same answer, so all three work. Two algorithms are deliberately left out: Argon2id and scrypt, which are designed to eat memory. CapSkip turns those down within about a third of a second instead of burning time on them, so a job that meets one fails fast and you know where you stand.
Related guides: ALTCHA in Python · ALTCHA in Node.js · ALTCHA in PHP
Does CapSkip open a browser to solve ALTCHA?
No. ALTCHA is a math task, not a page that has to be drawn, so CapSkip solves it as plain computation inside the app. No browser windows start, no memory goes to background tabs, and the same machine keeps doing its other work while challenges are being solved.
Will I have to buy proxies for ALTCHA work?
Not for the solving itself. ALTCHA judges the work your computer did, not where the request came from, so the solve needs none. If you let CapSkip fetch the challenge for you, it can use a proxy you already have, but the answer never depends on it.
Which ALTCHA versions and widget styles are covered?
Both generations that sites run: the older scheme and the current one, which ALTCHA recommends pairing with PBKDF2. The plain box, the checkbox and the switch are all handled, and CapSkip works out by itself which setup a site uses, so you never have to check before you start.
What kind of machine does ALTCHA solving need?
Very little. Each solve is a short burst of processor work with no browser behind it, so an everyday Windows PC or an entry-level VPS is enough. More cores simply mean more challenges solved side by side, because CapSkip sets no thread limit and each busy thread keeps one core occupied.
How long does one ALTCHA challenge take to clear?
Usually a few milliseconds, since your processor does the work locally, without an upload, a queue or a remote worker in between. Challenges that use an algorithm CapSkip does not cover are turned down in about a third of a second, so even a refusal never holds your job up for long.
Does solving more ALTCHA challenges raise my bill?
No. Your plan is priced by how many machines run CapSkip, from $35 a month for one, and the number of solves never enters the bill. A quiet day and a record day cost exactly the same, and re-solving a challenge that went stale is included as well.
Why would a correctly solved ALTCHA be rejected?
Nearly always because the challenge timed out. ALTCHA challenges carry a short expiry, sometimes barely two minutes, and a late answer fails exactly like a wrong one. Solve right before you submit instead of collecting challenges in advance. When CapSkip fetches the challenge itself, it grabs a fresh one if the first expired while waiting.
What happens when a site picks an algorithm CapSkip skips?
Some ALTCHA setups can be switched to Argon2id or scrypt, which are built to demand lots of memory. CapSkip declines those within about a third of a second and reports the challenge as unsolvable, so your job moves on instead of waiting. Every other ALTCHA setup, old or new, is solved as usual.
Put your own CPU to work on ALTCHA
Install the app on any Windows PC or VPS, sign in, and the ALTCHA challenges your tools meet are solved locally in milliseconds, while the monthly price never moves with the count.