All Tools
CompareStack offers nine free online utilities for document comparison and developer workflows. Each tool includes detailed instructions, use cases, limitations, and FAQs on its dedicated page. Browse by category below or use search to jump directly to JSON formatting, PDF comparison, SQL beautification, and more.
Which tool should I use? Choose Document comparison when you need to see what changed between two versions (text, PDF, Word, or Excel). Choose Developer tools when you need readable SQL, JSON, or indented snippets. Choose Encoding tools for URL percent-encoding or Base64 conversion. Unsure about document formats? Read Choosing the Right Document Compare Tool.
New to the platform? Start with the guides, a worked example for the tool you need, or the documentation for limits and troubleshooting. About CompareStack names who maintains the site.
Document comparison: Line- and row-oriented diffs for plain text, PDF contracts, Word drafts, and spreadsheet exports—best when review accuracy matters more than layout cosmetics.
Developer tools: Make minified SQL, JSON, and code snippets readable for pull requests, tickets, and documentation without opening a full IDE.
Encoding tools: Fix query-string and Base64 transport issues during API and OAuth debugging. Encoding is not encryption—always follow your security policy before pasting secrets.
Document comparison
Text Compare
Compare two text blocks and detect changed lines quickly.
Open Tool →PDF File Compare
Extract text from PDF files and compare for differences.
Open Tool →Word Document Compare
Compare Word documents by extracted textual content.
Open Tool →Excel File Compare
Compare Excel sheets by extracted rows and cell values.
Open Tool →Developer tools
SQL Formatter
Format SQL queries with improved readability and structure.
Open Tool →JSON Formatter
Validate and pretty print JSON responses and payloads.
Open Tool →Code Formatter
Apply basic indentation formatting for common code blocks.
Open Tool →Encoding tools
URL Encode / Decode
Encode and decode URLs and query parameters safely.
Open Tool →Base64 Encode / Decode
Encode text to Base64 or decode Base64 strings online.
Open Tool →