Spaces to Tabs Converter

Tab width defines how many spaces equal one tab character. 2 spaces is common in JavaScript, TypeScript, and web projects. 4 spaces is the Python standard (PEP 8) and common in C, Java, and general use. 8 spaces is the traditional Unix/C standard. Match the tab width to your project's coding style to ensure indentation levels align correctly after conversion.

With Leading spaces only enabled, the tool only converts spaces that appear at the start of each line (used for indentation). Spaces within the line — in string literals, comments, or inline alignment like x = 1 — are left untouched. This is the recommended mode for code because converting inline spaces would break string content, alignment patterns, and SQL formatting.

Mixed indentation means some lines are indented with spaces and others with tabs. This is a common problem when multiple developers use different editor settings or when code is pasted from different sources. It causes visual misalignment, confuses linters, and in Python it can cause TabError: inconsistent use of tabs and spaces in indentation. The tool detects and warns you when mixed indentation is present.

Only if used incorrectly. Python and YAML are indentation-sensitive — changing indentation characters changes the file's structure. Converting spaces to tabs in Python is safe only if every indentation level uses exactly the right number of spaces. Enable "Leading spaces only" and make sure your tab width matches the indentation in your file (usually 4 for Python). Always test the converted file after conversion.

In normal mode, exactly N spaces are replaced by one tab (where N is your tab width). So 4 spaces → 1 tab, 8 spaces → 2 tabs. With Collapse enabled, any sequence of one or more spaces (at the start of a line in leading-only mode) is replaced by a single tab, regardless of count. This is useful for normalising inconsistent indentation where some lines have 3 spaces and others have 5.

Yes — click Tabs → Spaces to reverse the conversion. Each tab character is expanded to your chosen number of spaces. This is useful when you receive code that uses tabs but your project requires spaces, or when preparing code to paste into a system that doesn't render tabs (like most web browsers and email clients).

No. Everything runs in your browser using JavaScript. Your code never leaves your device and is never sent to LazyTools or any third party. This makes it safe to use with proprietary code, client projects, and confidential source files.