Fact sheet · Developer Tools
CurlyJSON
JSON Formatter & Validator — Free, Private & Offline
Format, validate, beautify and repair JSON for free in your browser, even offline, keeping your data private.
Overview
CurlyJSON is a JSON formatter and validator that runs entirely in your browser without uploading data to servers. It formats, beautifies, validates and repairs invalid JSON, fixing common issues like trailing commas, single quotes, unquoted keys, comments, Python-style True/False/None, and JSON wrapped in extra text. The tool preserves large integers exactly as written, protecting 64-bit IDs from silent rounding, and includes a tree view for browsing large documents. Free tools are always private by default; optional Pro cloud AI for explaining and fixing JSON asks permission before sending data to Cloudflare.
Feature facts
- Validate JSON with precise line and column errors
- Repair invalid JSON fixing trailing commas, quotes, and comments
- Preserve large integers without rounding
- Detect and mask API keys, tokens and passwords
Pricing
Pricing model: Freemium
Free for all tools. Pro: $29.99 per year or $4 per month, plus tax.
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CurlyJSON specifications
| Section | Developer Tools |
|---|---|
| Website | curlyjson.com |
| Votes2 | 0 |
CurlyJSON metrics
| Metric | Value |
|---|---|
| Domain Rating | 0 no change since last check |
| Trust Flow | 7 no change since last check |
| Citation Flow | 13 no change since last check |
| Referring domains | 2 no change since last check |
| External backlinks | 7 no change since last check |
Fact: Ahrefs Domain Rating checked 12 Nov 2026, fact changed 1 Nov 2026. Fact: top topic Recreation/Travel (7). Fact: Majestic checked 1 Nov 2026, fact changed 1 Nov 2026. Link facts from Majestic. Trust Flow, Citation Flow and Topical Trust Flow are trademarks of Majestic-12 Ltd.
CurlyJSON domain fact sheet
Open the fact sheet
| Domain age | 29 days |
|---|---|
| Registered | |
| Expires | |
| Registrar | Cloudflare, Inc. |
| DNSSEC | Not signed |
CurlyJSON launch receipt sheet
What we have measured for CurlyJSON since it went live on SaaS Directory Info on 1 November 2026.
- 0 Domain Rating (Ahrefs) no change since launch
at launch: 0 (1 Nov 2026); latest: 12 Nov 2026 - 7 Trust Flow (Majestic)
first measured 1 Nov 2026 - 2 Referring domains (Majestic)
first measured 1 Nov 2026
Day 10 since launch. Next receipt: day 30, 1 Dec 2026. The figures report a change; they do not say what caused it, and many things can. No figure here is a guess.
Got a launch coming up?
Step-by-step tips for before, during and after your launch, free to read on SaaS Directory Info.
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Compare and explore
Frequently looked up
- Q1Is my JSON uploaded to a server?
- No. Formatting, validation and repair all run in your browser. Share links store the data in the part of the URL after the hash (#), which browsers never send to servers. You can verify this in your browser's Network tab.
- Q2Does it warn me about API keys and passwords?
- Yes. When your JSON contains secrets such as API keys (Stripe, AWS, GitHub, OpenAI and more), tokens, passwords, private keys or card numbers, a warning appears with a Hide button that masks them in place.
- Q3Why does this formatter keep my large numbers intact?
- Most online formatters use JavaScript's JSON.parse, which rounds integers above 9,007,199,254,740,991, silently corrupting 64-bit IDs. This tool keeps every number exactly as written.
- Q4What can Repair fix?
- Trailing commas, single quotes, unquoted keys, comments, missing commas or brackets, Python-style True/False/None, and JSON wrapped in extra text such as an AI chat reply or log line. After repair it lists every kind of fix made, and Undo restores the original text.
- Q5Is the AI free? Does it see my data?
- Explain and AI Fix are part of Pro. Repair, which fixes common mistakes without AI, is free. In desktop Chrome the AI runs on Chrome's built-in on-device model, so your JSON never leaves your computer. In other browsers Pro uses cloud AI only after you approve.
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CurlyJSON 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)
See also
| Product | Origin | DR1 | Votes2 |
|---|---|---|---|
| liquid-technologiesXML code generator for C# and Visual Basic .Net that creates strongly typed object models from XML schemas | United Kingdom | 70 | 0 votes. Log in to vote for liquid-technologies in the file |
 APIGitGit-native platform for building, publishing, sharing, and securing APIs | United States | 36 | 0 votes. Log in to vote for APIGit in the file |
 eryxWebAssembly sandbox for running untrusted Python safely | not stated | 0 | 0 votes. Log in to vote for eryx in the file |
 TestFlows MachineRun your programs deterministically. Record, replay, and branch your runs. | not stated | 2 | 0 votes. Log in to vote for TestFlows Machine in the file |