Format JSON
Beautify JSON with readable indentation directly in your browser.
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About JSON Formatter
JSON Formatter makes JSON easier to read by adding indentation and line breaks while keeping the data unchanged. It is useful for API responses, configuration files, debugging, and code review. Formatting happens in your browser so sensitive JSON stays local. Whether you are optimizing assets for a US-hosted site on AWS, Cloudflare, or Vercel, trimming email attachments for Gmail and Outlook, or submitting documents to federal portals, this tool keeps your files lean and your workflow fast — all without uploading anything to a server.
Optimized for Users in the United States
If you are working in the United States, file size matters for email providers like Gmail (25 MB attachment cap), Outlook, and popular US hosting platforms. Compressing images and documents before uploading to Amazon S3, Cloudflare, or Netlify keeps your bandwidth costs down and improves Core Web Vitals for American visitors on both fiber and mobile networks.
- Most US email services reject attachments above 25 MB — compress to stay under that limit without switching to Google Drive or Dropbox.
- For US-based e-commerce on Shopify, aim for product images under 200 KB to keep your Google PageSpeed score competitive.
- Social platforms popular in the US — Instagram, Facebook, X (Twitter), and LinkedIn — each re-encode uploads, so feed them the smallest high-quality source file you can.
- Many US government and healthcare portals restrict document uploads to 5–10 MB; pre-compressing PDFs avoids upload failures.
How to Format JSON Online
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1
Paste JSON into the editor
Copy your JSON object or array into the input panel.
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2
Choose indentation and format
Pick the indentation size you want and run the formatter to generate readable output.
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3
Copy or download the result
Review the formatted JSON, then copy it or save it as a JSON file.
Frequently Asked Questions
Does formatting change my JSON data?
No. Formatting only changes whitespace and indentation, not the keys, values, or structure.
Can I choose different indentation sizes?
Yes. You can switch between several indentation sizes before formatting the JSON output.
Is this JSON formatter private?
Yes. The formatting runs locally in your browser, so your JSON is not sent to our servers.
What happens if the JSON is invalid?
The tool shows that the JSON is invalid and reports the error location when the browser provides it.
Will this work with my Gmail or Outlook attachments?
Yes. Gmail and Outlook both cap attachments near 25 MB. Our tools can shrink most files well under that limit so you can attach them directly instead of linking to Google Drive or OneDrive.
Can I use this for sensitive business or healthcare documents?
Since all processing happens locally in your browser and nothing is uploaded, your files never touch our servers. This client-side approach supports privacy-conscious US workflows — still follow your own organization's data policies.
Does it work on Mac, Windows, and mobile?
Yes. Our tools run in any modern browser on macOS, Windows, ChromeOS, Linux, iOS, and Android. No downloads or installations required.
Is there a file size limit?
Most tools handle files up to 50 MB each. For larger files, process them in smaller batches for the smoothest experience.
Why Choose Let Compress?
- No upload required — your files stay on your device, aligning with US privacy expectations
- Free forever, no sign-up or credit card — we never sell your data
- Batch process dozens of files at once — built for fast US broadband and 5G workflows
- Tuned for US-hosted sites on AWS, Cloudflare, Vercel, and Netlify
- Runs in any modern browser — Chrome, Safari, Firefox, Edge on Mac, Windows, and mobile
- No file quotas or daily limits — compress as much as your project needs
Learn More About Image Compression
Explore these authoritative resources to deepen your understanding of image compression and optimization.
MDN Web Docs: Image Optimization
Comprehensive guide on image optimization for web performance by Mozilla.
Google Web Fundamentals: Image Optimization
Best practices for image optimization from Google's web performance team.
W3C WebP Specification
Official W3C specification for the WebP image format.