Private by default
Format JSON, convert files, and decode tokens in the tab. Core tools do not upload your payloads to our servers.
Tools by RS
Free Online Developer Tools - JSON, PDF & More
Tools by RS provides free, private developer tools (JSON, converters, PDF, encoding) that run in your browser - payloads are not uploaded for core utilities.
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89 tools · 12 categories · core utilities run in your browser
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Frequently opened tools from the registry.
- JSON FormatterPopular
Format, beautify, and minify JSON in your browser. Free, private, and instant - no upload to a server.
- JSON ValidatorPopular
Validate JSON instantly in your browser. See type, size, and node counts - or exact parse errors with line and column.
- JSON ViewerPopular
Explore JSON as an interactive tree with paths, types, and expandable nodes - all processed locally in your browser.
- Base64 Encode / DecodePopularNew
Encode UTF-8 text to Base64 or decode Base64 back to text - instantly in your browser.
- URL Encode / DecodePopularNew
Percent-encode text for URLs or decode encoded query strings - private and instant.
- JWT DecodePopularNew
Decode JWT header and payload in your browser - inspect claims without uploading tokens.
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Filter by category or scroll the full registry.
89 listed
- JSON FormatterPopular
Format, beautify, and minify JSON in your browser. Free, private, and instant - no upload to a server.
- JSON ValidatorPopular
Validate JSON instantly in your browser. See type, size, and node counts - or exact parse errors with line and column.
- JSON ViewerPopular
Explore JSON as an interactive tree with paths, types, and expandable nodes - all processed locally in your browser.
- JSON Compare
Compare two JSON documents structurally. Find added, removed, changed, and type-changed paths - privately in your browser.
- JSON Diff
Generate a unified diff of two JSON documents after pretty-printing. Ideal for reading line-level changes quickly.
- JSON Escape
Escape text into a JSON string literal, or unescape a JSON string back to raw text - instantly and offline.
- Base64 Encode / DecodePopularNew
Encode UTF-8 text to Base64 or decode Base64 back to text - instantly in your browser.
- URL Encode / DecodePopularNew
Percent-encode text for URLs or decode encoded query strings - private and instant.
- JWT DecodePopularNew
Decode JWT header and payload in your browser - inspect claims without uploading tokens.
- UUID GeneratorPopularNew
Generate UUID v4 identifiers in bulk - uppercase and hyphenless options, fully client-side.
- Regex TesterPopularNew
Test JavaScript regular expressions against sample text - matches and groups, private in your browser.
- Timestamp ConverterPopularNew
Convert Unix timestamps to dates and back - seconds, milliseconds, and ISO strings in your browser.
- Markdown PreviewPopularNew
Preview Markdown as HTML in your browser - private drafts, no upload.
- HTML Email PreviewPopularNew
Preview HTML email with estimated client compatibility - private sandbox, no upload.
- HTML EscapePopularNew
Escape and unescape HTML entities in your browser - private encode/decode, no upload.
- Hash GeneratorPopularNew
Generate SHA-1 / SHA-256 / SHA-384 / SHA-512 digests of text with Web Crypto - fully client-side.
- Case ConverterNew
Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case, and more.
- Word CounterNew
Count words, characters, sentences, and paragraphs with reading time - live and private.
- Text DiffNew
Compare two texts line by line - see added and removed lines with a unified-style diff.
- Slug GeneratorNew
Turn titles into clean, SEO-friendly URL slugs - lowercase, hyphenated, accents stripped.
- Lorem Ipsum GeneratorNew
Generate placeholder text by paragraphs, sentences, or words - deterministic and offline-friendly.
- Image CompressorPopularNew
Compress JPG, PNG, and WebP images in your browser with a quality slider - private, no upload.
- Image ResizerNew
Resize images by width or height in your browser - keep aspect ratio or stretch to exact pixels.
- Image ConverterPopularNew
Convert images between PNG, JPG, and WebP in your browser - private, no upload.
- Image CropperNew
Crop images by pixel coordinates in your browser - JPG, PNG, WebP, private, no upload.
- Meta Tag GeneratorPopularNew
Generate title, description, canonical, Open Graph, and Twitter meta tags as paste-ready HTML.
- Robots.txt TesterNew
Test whether a path is allowed by robots.txt for a user-agent - local Allow/Disallow matching.
- SERP PreviewNew
Preview title, URL, and meta description as a search snippet with character budgets - private and local.
- Open Graph DebuggerNew
Inspect Open Graph and Twitter Card tags from pasted HTML - find missing fields locally, no URL fetch.
- JSON Schema GeneratorPopularNew
Infer a draft-07 JSON Schema from sample JSON - local-first, private, optional rate-limited API.
- Regex ExplainerPopularNew
Explain JavaScript regex patterns - tokens, groups, and flags - privately in your browser.
- QR Code GeneratorPopularNew
Generate a PNG QR code from text or a URL - private, browser-only.
- Color ConverterNew
Convert between hex, RGB, and HSL color notations - private and client-side.
- Contrast CheckerNew
Check WCAG contrast ratio for foreground and background hex colors.
- Gradient GeneratorNew
Build linear and radial CSS gradients with Tailwind output - private and client-side.
- Merge PDFPopularNew
Combine multiple PDF files into one document entirely in your browser.
- Split PDFPopularNew
Extract a page range from a PDF into a new file in your browser.
- Rotate PDFPopularNew
Rotate PDF pages by 90°, 180°, or 270° entirely in your browser.
- Compress PDFPopularNew
Rewrite a PDF locally to shrink structural overhead. Results vary for image-heavy scans.
- Images to PDFPopularNew
Turn one or more JPG/PNG images into a PDF in your browser.
- JPG to PDFNew
Convert JPG/JPEG images to PDF locally in your browser.
- PNG to PDFNew
Convert PNG images to PDF locally in your browser.
- WEBP to PDFNew
Decode WEBP in the browser, then embed as PDF pages. Uses canvas conversion locally.
- PDF to JPGPopularNew
Render PDF pages to JPG images locally in your browser.
- PDF to PNGNew
Render PDF pages to PNG images locally in your browser.
- PDF to ImagesPopularNew
Render PDF pages to JPG or PNG images locally in your browser.
- PDF to TextPopularNew
Extract existing text from PDFs locally. Scanned PDFs need OCR PDF instead.
- OCR PDFNew
Run OCR on PDF pages locally with Tesseract. Slower and page-capped; best for short scans.
- Repair PDFNew
Rebuild a PDF by copying pages into a new document. Helps mild structural issues - not magic recovery.
- PDF to CSVNew
Extract PDF text and split lines into CSV heuristically. Best for simple layouts.
- PDF to ExcelPopularNew
Export PDF text to CSV for Excel. Heuristic tables - open the CSV in Excel or Sheets.
- Bank Statement PDF to ExcelPopularNew
Export bank statement PDF text to CSV for Excel. Heuristic - always review amounts.
- PDF Sign (local)New
Stamp a local signature name on the last PDF page. Not a full e-signature product.
- HTML to PDFPopularNew
Convert HTML to a simple text-layout PDF locally. Not a pixel-perfect print engine.
- DOCX to PDFPopularNew
Convert DOCX to PDF locally via HTML extraction. Complex layouts may lose fidelity.
- Word to PDFNew
Convert Word (DOCX) to PDF locally. Alias intent for DOCX to PDF with Word-focused copy.
- PDF to WordPopularNew
Extract PDF text into a simple DOCX. Layout is not preserved perfectly.
- Barcode GeneratorPopularNew
Generate Code128, EAN, UPC, and Code39 barcodes as PNG in your browser.
- JSON to XMLPopularNew
Convert JSON to XML privately in your browser.
- JSON to CSVPopularNew
Convert JSON to CSV privately in your browser.
- JSON to YAMLPopularNew
Convert JSON to YAML privately in your browser.
- JSON to TSVNew
Convert JSON to TSV privately in your browser.
- JSON to StringNew
Convert JSON to string privately in your browser.
- JSON to HTMLNew
Convert JSON to HTML privately in your browser.
- XML to JSONPopularNew
Convert XML to JSON privately in your browser.
- XML to CSVNew
Convert XML to CSV privately in your browser.
- XML to StringNew
Convert XML to string privately in your browser.
- XML to YAMLNew
Convert XML to YAML privately in your browser.
- RSS to JSONNew
Convert RSS/XML to JSON privately in your browser.
- YAML to JSONPopularNew
Convert YAML to JSON privately in your browser.
- YAML to XMLNew
Convert YAML to XML privately in your browser.
- YAML to CSVNew
Convert YAML to CSV privately in your browser.
- YAML to TSVNew
Convert YAML to TSV privately in your browser.
- CSV to JSONPopularNew
Convert CSV to JSON privately in your browser.
- CSV to XMLNew
Convert CSV to XML privately in your browser.
- CSV to YAMLNew
Convert CSV to YAML privately in your browser.
- CSV to HTMLNew
Convert CSV to HTML privately in your browser.
- TSV to JSONNew
Convert TSV to JSON privately in your browser.
- TSV to CSVNew
Convert TSV to CSV privately in your browser.
- String to JSONNew
Convert string to JSON privately in your browser.
- Base64 Encode TextNew
Encode plain text notes, messages, and Unicode strings to Base64 in your browser - private and instant.
- Base64 Encode JSONNew
Encode JSON payloads to Base64 for APIs, JWTs, and transport - decode back to UTF-8 JSON in your browser.
- Base64 Encode HTMLNew
Encode HTML fragments and markup to Base64 for data URLs, emails, and embeds - decode back in your browser.
- Base64 Encode URLNew
Encode URLs and query strings to Base64 for opaque links and redirects - distinct from percent-encoding.
- Gmail Email PreviewNew
Preview HTML email with Gmail-focused estimated compatibility checks - private browser sandbox.
- Outlook Email PreviewNew
Preview HTML email with Outlook-focused estimated warnings for Word-based rendering risks.
- Email Dark Mode TesterNew
Test HTML email dark-mode risks with light/dark preview chrome and color heuristics - private and client-side.
- Responsive Email TesterNew
Test HTML email at common device widths with estimated media-query guidance - private browser sandbox.
- HTML UnescapeNew
Decode HTML entities to plain text in your browser - named and numeric references, CMS and Power Automate friendly.
Why use Tools by RS
One search, full catalog
Jump straight to the utility you need: JSON, PDF, encoders, converters, SEO helpers, and more from a single command bar.
Built to be cited
Each tool ships a direct answer, examples, FAQs, and structured data so assistants and docs can quote accurate privacy claims.
Frequently asked questions
Privacy, pricing, and how this site differs from upload-based tools.
Does Tools by RS upload my data?
No for core client-side tools. Formatting, conversion, encoding, and most PDF utilities process input in your browser. Prefer pages that state browser/local processing when privacy matters.
Why use this site instead of upload-based converters?
Upload-based converters send files to someone else's servers. Tools by RS keeps everyday developer chores on-device, with unique per-tool documentation, FAQs, and examples assistants can cite accurately.
Are the tools free?
Yes. Core tools are free to use without an account. Limits exist to protect browser performance, not to gate conversion behind signup.
Machine-readable catalog: /llms.txt.