Developer Tools
Castov
Fast, 100% client-side developer platform with zero-data logging
Browser-based and CLI developer tools for timestamps, time zones, JSON conversion, and cryptography that run locally with no data logging.
Overview
The Castov homepage
Castov is a developer platform offering 61 free tools accessible through a web interface, command-line interface, and Model Context Protocol server for AI editors like Cursor and Claude. All conversions run locally in the browser using JavaScript with zero server data logging. The toolkit covers timestamp and date conversion, time zone operations, JSON formatting and validation, cryptographic utilities, and developer-focused tools like JWT decoding, UUID generation, and cron expression parsing.
The platform emphasizes privacy and performance: processing happens entirely client-side, payloads are never sent to external servers, and results are delivered with sub-millisecond latency. Advanced features include encrypted URL shares, end-to-end encrypted team vaults for environment variables, P2P multiplayer canvas for visual pipeline building, and steganography for hiding encrypted secrets in image pixels. Castov CLI is available via npm (v1.5.0) and the platform is deployable in Docker containers, CI/CD pipelines, and integrated with VS Code and other developer tools.
Capabilities
- Multi-timezone support with IANA database and daylight saving time
- JSON to TypeScript conversion
- JWT decoder and inspection
- Cron expression parser and generator
- End-to-end encrypted environment variable vaults
- P2P multiplayer canvas with WebRTC and CRDT
- Steganography for hiding encrypted secrets in images
- Service Worker API mocker for frontend testing
- Encrypted URL shares with hash fragment storage
Pricing
Pricing model: Free
All tools are free with no usage limits. The site may show ads in the future to cover running costs.
Follow Castov to get an email when they post a milestone, ship a new product or add a demo video.
Castov fact sheet
| Community votes | 0 |
|---|---|
| Website | castov.com |
Castov metrics
Vendor metrics for castov.com: Ahrefs Domain Rating and Majestic link data, with the delta since the last review.
- Domain Rating
- 1
- +1 (up) since last check
- Trust Flow
- 1
- no change since last check
- Citation Flow
- 19
- no change since last check
- Referring domains
- 7
- no change since last check
- External backlinks
- 14
- no change since last check
Vendor Domain Rating (Ahrefs) checked 6 Nov 2026, spec changed 2 Nov 2026. Vendor topic: Regional/Asia (1). Vendor Majestic data checked 31 Oct 2026, spec changed 31 Oct 2026. Link metrics supplied by Majestic. Trust Flow, Citation Flow and Topical Trust Flow are trademarks of Majestic-12 Ltd.
Castov vendor domain
Open the vendor record
We read this from the registry's RDAP record on 3 Nov 2026, 05:33 UTC.
- Domain age
- 11 months
- Registered
- Expires
- Registrar
- GoDaddy.com, LLC
- DNSSEC
- Not signed
Castov post-launch report
| Measure | At launch, then latest |
|---|---|
| Domain Rating (Ahrefs) | 0 to 1 +1 (up) since launch 31 Oct 2026, then 6 Nov 2026 |
| Trust Flow (Majestic) | 1 first measured 31 Oct 2026 |
| Referring domains (Majestic) | 7 first measured 31 Oct 2026 |
Day 5 since launch. Next receipt: day 30, 30 Nov 2026. Many things move these figures, so a change is not proof of cause. Only stored readings are shown.
About to launch?
Plan your launch with our free playbook, from preparing your listing to choosing more launch directories.
- The week before
- On the day
- Week one
- Beyond launch
Buyer questions
Is Castov really free?
Yes. All tools are free, with no account and no usage limits. The site may show ads in the future to cover running costs.
Is my data sent to a server?
Time, date and converter tools do not upload input to Castov servers. Some preferences like theme and time zones are stored locally. Some features use the network by design: Env Vault uploads an encrypted copy, P2P Ghost Tunnel uses public STUN discovery with manual token exchange, and Developer Canvas connects to public WebRTC signaling servers which may receive connection metadata but never store workflow graphs or payloads.
What is a Unix timestamp?
A Unix timestamp is the number of seconds since 1 January 1970 at 00:00:00 UTC. It identifies one moment in time regardless of time zone, which is why programs and APIs use it.
Which time zones are supported?
All IANA time zones supported by your browser are supported, such as America/New_York, Europe/Paris, Africa/Algiers and Asia/Tokyo, with daylight saving time rules applied for the date you choose.
Should I use seconds or milliseconds?
Use whichever your system produces. A 10-digit value is in seconds and a 13-digit value is in milliseconds. The converters can detect the unit for you.
Leave a review for Castov
No customer reviews of Castov yet. Write the first. Customer reviews are free and nobody can buy them.
Castov has a free listing. The owner can unlock the full profile with a paid launch for $5:
- Founder story (locked)
- Milestones (locked)
- Demo video (locked)
- Dofollow website link (locked)
Compare with
| # | Product | DR | Votes |
|---|---|---|---|
| 1 |  Swastik CodesWeb-based API platform for designing, testing, mocking, monitoring and documenting REST, GraphQL, gRPC, WebSocket, MQTT and MCP APIs |
2 no change since last check | 0 votes. Log in to vote for Swastik Codes as a buyer |
| 2 |  Validate |
9 no change since last check | 0 votes. Log in to vote for ValidateHTML as a buyer |
| 3 |  Build |
0 no change since last check | 0 votes. Log in to vote for BuildFerry as a buyer |
| 4 |  FiveM Backdoor ScannerFree browser-based scanner to detect hidden code, loaders and credentials in FiveM resources |
29 no change since last check | 0 votes. Log in to vote for FiveM Backdoor Scanner as a buyer |