Which forms attract bots
Anything public with a text field and no login: contact forms, giveaways, open polls, event sign-ups, job applications on a careers page. Bots fill them with spam links or stuff a vote. A form shared only inside a company chat rarely needs a captcha, and it adds a step for every real person.
Put the block right before the last screen. Respondents have already invested in the answers and won’t drop out at the final check the way they might on the first screen.
Setting it up: key, test mode and language
A new block starts in test mode with a public test key, which lets everyone through; that is useful while you build, and useless in production. Get a client key (it starts with «ysc1_») from Yandex SmartCaptcha, paste it into the block and switch test mode off.
An honest caveat for English-language surveys: the SmartCaptcha widget interface is shown in Russian. Most people just tick the box, but if a challenge appears, its instructions will be in Russian. Weigh that before adding the block to a form for an international audience.
The check is required by default. If the token expires or the network drops, the block clears it and the respondent passes the check again. It takes no column in results.
What you can set
- Yandex SmartCaptcha key
- test mode, lets everyone through
Alternatives to a captcha
Sometimes a captcha is the wrong fix. If spam comes through one shared link, publish the survey inside your site with the widget instead of posting the raw link on a public forum.
If the problem is repeat voting rather than bots, a captcha will not stop a determined person from voting twice. Think about how you distribute the link, or ask for an email and check duplicates in the CSV.
And for a survey sent to your own customers or staff, you know who they are already; the captcha only slows them down.