Free Online Tools - CheckKit

This group handles publicly visible social data: whether a username or UID still opens, public profile fields, follower/following samples, and ZIPs of public posts or stories. They do not read private content and are not official platform APIs.

• Instagram Username Live Check

  Paste usernames to check live / die (no paid profile fields).

• Instagram Public Region Lookup

  Batch-resolve Instagram account countries.

• Instagram Public Profile View

  Batch-fetch basic Instagram profile fields.

• Instagram Public Posts ZIP

  Collect post media and generate a ZIP download.

• Instagram Public Stories ZIP

  Collect story media and generate a ZIP download.

• Instagram Public Followers Sample

  List followers of a public account (subject to upstream limits).

• Instagram Public Following Sample

  List accounts a public profile follows (subject to upstream limits).

• Facebook UID Live Check

  Paste Facebook UIDs and probe live / die via the public avatar.

• Facebook Public Friend Count

  Paste UIDs to batch-query friend counts and profile fields.

• Facebook Username to UID

  Paste a username or profile URL to resolve the numeric UID.

• Threads Public Live Check

  Paste Threads / Instagram usernames to check live / die.

• TikTok Public Live Check

  Paste TikTok usernames to check live / die.

• X Public Live Check

  Paste X / Twitter usernames to check live / die.

Email tools split in two: some only inspect addresses, servers, or headers and never send mail; Outlook reading needs a refresh token you already authorized, and only for mailboxes you may access.

• Gmail Address Check

  Paste @gmail.com addresses (up to 10 per run).

• Outlook Authorized Mail Read

  Format: email|refresh_token|client_id.

• SMTP Short Connection Test

  Check the SMTP banner, STARTTLS, and connectivity.

• Domain MX Record Lookup

  View a domain’s mail exchanger records.

• Raw Email Header Parser

  Paste raw headers to inspect routing and authentication fields.

These tools query public hosts or DNS from the server to confirm resolution, certificates, headers, and ports. Results are what the CheckKit server saw then, and may differ from your machine or another region.

• Domain DNS Record Lookup

  Look up A / AAAA / CNAME / MX / TXT / NS.

• Current Public IP

  Show the public IP seen when your browser visits this site.

• Hostname and IP Resolve

  Look up resolution info for a host or IP.

• Public TCP Port Probe

  Check whether a port is open on a public host.

• HTTP Response Header View

  View HTTP response headers for a URL.

• SSL Certificate Info

  View the subject, issuer, and validity of an HTTPS host certificate.

Almost all of these run in the browser: paste text and get a result without uploading it to CheckKit. Useful for API samples, list cleanup, cookie conversion, and scratch notes.

• Local JSON Formatter

  Format, minify, and validate JSON in the browser.

• Local URL Encoder Decoder

  Encode or decode URL strings in the browser.

• Timestamp and Date Convert

  Convert between Unix timestamps and readable dates.

• UA String Parser

  Extract browser, OS, and device hints from a UA string.

• Cookie Format Convert

  Convert between HTTP Cookie, JSON, and Netscape formats.

• List Text Cleaner

  Trim, dedupe, sort, change case, and extract emails.

• Delimited Text to Table

  Split text into a table and copy CSV / TSV.

• Browser Local Notes

  Browser-local notes, with optional password and share link.

Passwords, random strings, hashes, and 2FA are computed in the browser. Secrets and hashed text are not uploaded. These tools generate and check; they do not store a password vault or claim to be an official authenticator.

• Local Random Password Tool

  Generate random passwords in the browser.

• Local Password Strength Estimate

  Estimate password strength in the browser.

• Local SHA Digest

  Compute SHA-1 / SHA-256 / SHA-512 in the browser.

• Local Random String Tool

  Generate random strings for tokens and tests.

• Local TOTP Authenticator

  Generate TOTP locally. Accepts a secret, or UID|password|2FA (3rd field).