ST4LK

ST4LK watches your competitors' Instagram and X accounts, logs the people who just followed them and ranks each one by how closely they match your ideal customer. Every day, the tool shows a list of named profiles sorted by a score from 0 to 100. Each score comes with a sentence that explains it and, for the best profiles, an email address found on their website.

Instagram and X show the follower list of any public account, with no date for each follow. Someone who followed a competitor this week is likely comparing options right now. ST4LK turns that signal into a list of prospects you can contact one at a time.

How it works

1. The accounts you watch

You paste the public URL of an Instagram or X profile: a competitor, a neighbouring brand, a creator in your niche, or your own account. ST4LK detects the platform from the link. You give no access to the watched account, and the tool never asks for your own login: it reads public information only. On X, it reads accounts through the platform's official API.

2. Your business description

When you sign up, you describe your company. You can enter your website URL: ST4LK drafts a description from it, which you then edit, along with your ideal customer and scoring instructions. All the scoring starts from this profile.

3. New follower detection

When you add an account, ST4LK takes a first snapshot of its audience. These starting followers form the comparison base and never show up as new. The tool then re-checks the account on your plan's schedule, from every six hours down to every thirty minutes. When the count goes up, it pulls the latest arrivals, drops anyone it has already seen and keeps only the unknown ones. Each tracked account shows a follower chart and the list of newcomers, sorted by score.

4. Three-stage scoring

Each new follower goes through a scoring cascade, where only a promising profile moves on to the next, more expensive stage:

• A free, instant first score, computed from signals already on hand: business account, website, bio, category, audience size, verified badge, activity. A private account loses points.
• An AI read of promising profiles, which compares the lead's bio and profile with your business description, adjusts the score and writes the reason.
• Deep web research on the best profiles: searches on the name, the handle and the website, then a crawl of the lead's site. This is the stage where the email turns up.

Results come in four tiers: HOT from 75, WARM from 50, TIÈDE from 30, FROID below that. When the same person follows several of the competitors you watch, ST4LK flags them with a badge and raises their score on every card where they appear. The site describes this as a sign that the person is shopping.

5. What you get on each lead

For each lead, you see the handle, name, bio, audience, score, the reason for the score and, when there is one, the email found with its source. A recap email flags new leads scored 75 or above. Emails come from public sources only, mainly the lead's own website and the pages it links to, and each lookup uses one credit from your monthly quota. A lookup that finds nothing costs no credit.

Use cases for an early-stage startup

• Finding your first customers on Instagram. You sell to studios, brands or freelancers who are active on Instagram: you watch three to five direct competitors and contact the new followers ranked HOT each week.
• Prospecting founders and product teams on X. The ST4LK blog suggests watching a competitor's company account and its founder's account, along with podcasts or events in your field, whose new followers have just shown interest in the topic.
• Spotting buyers who compare. A person who follows several competitors in the same week moves to the top of the list thanks to the multi-follow bonus.
• Qualifying your own audience. You add your own account: new followers who fit your offer came to you, which justifies a more direct message.
• Checking a positioning before paying for ads. Before a campaign, you read the profiles joining the accounts in your market to see which people take an interest in your category.

For outreach, read the ST4LK guide on turning competitors' followers into leads. This guide recommends opening with a public reply or a personal message written by hand, and never mentioning that the person followed a competitor. To compare ST4LK with other tools, see our guide to B2B prospecting tools.

Pricing and access

The prices on the ST4LK pricing grid are monthly, in euros:

The trial costs €19 as a one-off payment and runs the Solo plan for seven days, with ten email lookups. The trial does not renew: ST4LK charges nothing when it ends, and you pick a monthly plan if you want to continue. Beyond your quotas, you can buy a pack of 50 email lookups for €29 or an extra tracked competitor, billed between €80 and €150 per month depending on the plan. Payment goes through Stripe, and you change or cancel your plan from your customer portal.

Sign-up requires an invite code: the ST4LK sign-up page asks for one to create an account.

Limits

• Two platforms. ST4LK covers Instagram and X, on public accounts only. LinkedIn, TikTok and Facebook are out of scope.
• Detection between two checks. Neither Instagram nor X shows the date of a follow, so ST4LK compares two snapshots. On a very large account that gains many followers between two checks, the tool only catches part of the arrivals, and the site states that it cannot promise to catch every new follower on X. When new follows offset unfollows, the count barely moves and those new followers can go unnoticed.
• No unfollower tracking. You see who arrives, with no record of who leaves.
• AI scoring from the Pro plan up. The Solo plan, and therefore the trial, lists basic enrichment without the "AI scoring" line.
• No guaranteed email. The tool looks for a public address; for a profile with no website or listed contact, you can only reach the person on the platform.
• Outreach is your job. ST4LK sends no messages. X forbids unsolicited direct messages sent in bulk or by automation, and the GDPR requires you to tell people where their data came from, at the latest in your first message. ST4LK offers a one-click opt-out and a permanent suppression list.
• An English-only interface, with no CRM integration listed on the site.

Origin

swanbase built its tools with AI in 2026 and opened four of them to founders: fog, ST4LK, Nametlas and Press3D Paris. The team practises the acquisition channels it teaches, outbound prospecting included. The demo workspace shown on the ST4LK home page is named after swanbase.