Answers about local processing, offline access and getting a useful result. For a tool’s exact syntax and limits, check its detail page.
Browse all tools · Read the offline guide · Privacy details
Getting started
Do I need an account, subscription or API key?
No. All 40 tools are free to use without signing in, subscribing or supplying an API key. Open All tools, choose a task and select Load example, then Run tool.
Where can I find instructions and a known result?
Every tool page includes How to use, A worked example, Expected result and Scope & limitations. Load example restores the sample inputs. When changing an operation, check that your input matches the new mode: for example, JSON Patch Apply needs a patch array, not a target document.
Does the site run generated code or make API requests?
No. cURL conversion produces Fetch code but never sends the request. SQL and configuration builders return text without executing it. HAR analysis reads recorded requests without replaying them. External documentation is optional and opens only when you follow a link.
Privacy and local files
Are my text and files uploaded?
Tool calculations and file reads happen in your browser. This build does not upload tool inputs or use runtime third-party APIs, analytics or advertising scripts. Loading and updating the website still contacts its host, which can receive ordinary request metadata. Browser extensions and translation services have their own data practices.
Does the website remember my inputs?
The application does not deliberately save tool inputs or results. It saves your theme preference and caches website pages and assets for offline use. Your browser may restore forms or tabs, and copied or downloaded results can remain on your device. Clear removes visible inputs and output; it does not erase your clipboard or downloaded files.
What are the file and text limits?
Most text inputs are limited to 2 million characters, with smaller limits on some tools. The hex viewer displays the first 64 KiB and reports truncation. Text encoding and HAR file inputs allow files up to 2 MiB. Other tools limit records, operations or path length; read the specific page before processing a large input.
Offline use and updates
How do I prepare the site for offline use?
Open the site while connected and wait for the footer status to read “Offline ready · all 40 tools cached”. Preparation caches tool pages, guides, this FAQ and bundled assets. Use the same site address, browser profile and device when you return offline. Installing the site as an app is optional.
Why does offline mode stop working in another browser or after clearing data?
Offline storage belongs to a particular browser profile and site origin. A different domain, port, browser or device needs its own preparation. Clearing site data, private browsing restrictions, storage limits or browser eviction can remove the cache. Reconnect and wait for Offline ready again; opening downloaded HTML through file:// is not equivalent to visiting the site.
What should I do if offline preparation never finishes?
Keep the connection available and reload the page. Check whether your browser permits service workers and site storage, and whether storage space is available. If you clear site data to retry, your theme preference and offline copy will also be removed. Prepare again online before testing offline access.
How do updates reach the offline copy?
When connected, the site prepares a complete new cache before activating it. Reload to use the activated version. An offline visit cannot download an update; reconnect first. Cached tool inputs are not part of this update process because the application does not deliberately store them.
Results and troubleshooting
Can I use generated results directly in production?
Review the worked example and scope, then test your own inputs and outputs in a suitable environment. Sample-based types and schemas describe observed data, not a complete business contract. Cookie and cache reports are limited diagnostics, not proof of browser acceptance. Review generated SQL, code and configuration before execution.
Why did an input produce an error?
Check the selected mode, required fields, syntax and size limits. JSON must use valid JSON syntax; a JSON Pointer is not JSONPath; byte converters require complete hex pairs. Try Load example and Run tool to establish a known result, then reduce your input to the smallest case that reproduces the issue. Errors clear the previous output so it cannot be mistaken for a new result.
Why do large JSON numbers lose digits?
JSON-based tools use JavaScript binary64 numbers. Integers outside the safe range can lose precision when parsed, and decimal fractions can round. Keep identifiers that need exact digits as JSON strings. Numeric overflow such as 1e400 is rejected; these tools do not provide arbitrary-precision JSON arithmetic.
Why is a successful output blank?
An empty result can be correct: an empty array converted to NDJSON, empty Base32 text or an extracted empty JSON string produces empty text. The Done status identifies a successful empty result, and Copy result and Download text remain available. A downloaded empty result is a zero-byte file. A blank output after Error is different.
What if copying or downloading does not work?
Run the tool successfully first. Clipboard access depends on browser permissions and a supported secure context; if copying fails, select the output and copy it manually. Download text creates a local text file; check your browser’s download permissions and download list. Clear disables both buttons until another result is generated.
How can I report an unexpected result?
Use the Contact page for the available contact information. Include the tool name, browser version, selected options, a minimal non-sensitive input, the actual result and what you expected. Remove passwords, tokens and private records. Entering information into a tool does not submit a bug report.
Need to report an issue? See contact information and what to include.