Online utilities are useful for quick, one-off transformations when installing a package or writing a script would take longer. Choose a tool that clearly states what it changes, test it with a small sample and keep a copy of the original input.
1. Format and validate JSON
When an API response is difficult to read, paste a non-sensitive sample into a JSON formatter. Pretty-printing adds indentation; validation helps identify malformed syntax such as a missing comma, unmatched quote or trailing comma. For example, {"name":"Mira","active":true} can be expanded into readable multi-line JSON. Formatting does not verify that the data matches your application's schema.
Open the JSON Formatter · Read the JSON formatting guide
2. Encode URL components, not whole URLs by accident
Use component encoding when inserting a value into a query parameter. A value such as summer sale & offers contains spaces and an ampersand; encoding it prevents the ampersand from being interpreted as a separator between parameters. Do not repeatedly encode a value that is already encoded, and distinguish component encoding from full-URL encoding.
Open the URL Encoder / Decoder
3. Convert text to and from Base64 when a format requires it
Base64 represents bytes using printable characters. It is commonly used to carry binary data through text-oriented formats, but it is not encryption and does not protect secrets. Check whether the receiving system expects UTF-8 text, raw bytes or a data URL prefix before copying the output.
Open the Base64 Encoder & Decoder · Open the Image to Base64 Converter
4. Test regular expressions with positive and negative examples
A regex should match intended inputs and reject near misses. For a simple identifier made of two uppercase letters followed by four digits, try \b[A-Z]{2}\d{4}\b. Check AB1234 as a positive example and A1234, ABC1234 and ab1234 as negative examples unless case-insensitive matching is intended. This checks text shape only; it does not prove that an identifier exists.
Open the JavaScript Regex Tester · Read the regex testing guide
5. Convert CSV and JSON carefully
CSV is convenient for spreadsheets, while JSON is common in APIs. Before converting, check whether the first row contains headers, whether fields contain commas or quotation marks, and whether nested JSON values need a custom mapping. Compare the converted row count and inspect several records instead of assuming a successful conversion means the data is correct.
CSV to JSON · JSON to CSV · CSV Viewer
Keep sensitive data out of public tools
Do not paste passwords, access tokens, private customer records, production API responses or confidential source code into a website unless you have checked how that specific tool handles input. Many Tolvix utilities run in the browser, but some features use third-party services or libraries. Read the individual tool's privacy note and the Tolvix Privacy Policy before using sensitive material.
A quick result-check routine
- Keep the original input so you can compare or undo the transformation.
- Test a normal example, an empty value and at least one edge case.
- Check character encoding, whitespace, line endings and special characters.
- Validate the output in the actual application or runtime that will consume it.
- Do not treat encoding as encryption or formatting as schema validation.