toolsku
Free online toolbox for everyday tasks
300+ free online tools for images, PDF, JSON, and text. Runs locally in your browser—no signup required.
Quick Access
One-click access to frequently used tools
PDF Tools
Merge, split, convert to/from images, reverse page order, metadata, watermark, compress, and more — all processed locally in your browser. 100% free, runs locally in your browser—nothing is uploaded to our servers.
PDF to Word
EnterConvert PDF to editable DOCX. Free PDF to Word online tool
PDF to Excel
EnterConvert PDF to XLSX. Free PDF to Excel online tool
PDF to Image
EnterExport each page as PNG/JPG/WebP, ZIP download, adjustable scale. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Images to PDF
EnterCombine PNG/JPEG into a PDF, one image per page. 100% free, runs locally in your browser—nothing is uploaded to our servers.
PDF Merge
EnterConcatenate multiple files in order. 100% free, runs locally in your browser—nothing is uploaded to our servers.
PDF Split
EnterExport page by page or group by a fixed page count. 100% free, runs locally in your browser—nothing is uploaded to our servers.
PDF Rotate
EnterApply 90°/180°/270° rotation to selected pages. 100% free, runs locally in your browser—nothing is uploaded to our servers.
PDF Delete Pages
EnterCheck pages to delete; remaining pages keep original order. 100% free, runs locally in your browser—nothing is uploaded to our servers.
PDF Crop Margins
EnterRemove black edges or whitespace, with page selection and pt margins. 100% free, runs locally in your browser—nothing is uploaded to our servers.
JSON Tools
Format, YAML/TOML/CSV conversion, JSONPath, JMESPath, structural diff, TypeScript types—all under /json. 100% free, runs locally in your browser—nothing is uploaded to our servers.
JSON Formatter
EnterFormat, minify, and validate JSON syntax, all processed locally in browser. 100% free, runs locally in your browser—nothing is uploaded to our servers.
YAML ↔ JSON
EnterConfig file format conversion (js-yaml). 100% free, runs locally in your browser—nothing is uploaded to our servers.
TOML ↔ JSON
EnterConfig format conversion (@iarna/toml). 100% free, runs locally in your browser—nothing is uploaded to our servers.
JSON ↔ CSV
EnterConvert between object array and CSV table. 100% free, runs locally in your browser—nothing is uploaded to our servers.
JSONPath
EnterExtract nodes from JSON (jsonpath-plus). 100% free, runs locally in your browser—nothing is uploaded to our servers.
JMESPath
EnterQuery JSON with JMESPath (jmespath). 100% free, runs locally in your browser—nothing is uploaded to our servers.
JSON Diff
EnterTree-shaped delta (jsondiffpatch). 100% free, runs locally in your browser—nothing is uploaded to our servers.
JSON → TypeScript
EnterHeuristically generate interface from sample JSON. 100% free, runs locally in your browser—nothing is uploaded to our servers.
JSON → Go
EnterGenerate Go struct from JSON. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Text Processing
Case conversion, line sorting/cleanup, HTML to plain text, indent, line numbers, line wrapping, statistics, find & replace, regex, diff, Lorem, slug, ROT13, and more. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Case & Naming
EnterUpper/lower, title case, camelCase, kebab-case, snake_case, CONSTANT_CASE, etc. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Line Cleanup
EnterSort, deduplicate, remove blank lines, trim each line, reverse line order. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Word Count
EnterLines, characters, words, UTF-8 bytes, grapheme clusters. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Word & Character Counter
EnterCount words, characters, lines, and UTF-8 bytes in real time—for essays, blogs, and copy. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Find & Replace
EnterLiteral or regex replacement with configurable flags. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Split / Join
EnterSplit into multiple lines by delimiter, or join lines with delimiter. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Regex Playground
EnterMatch, groups, and highlight preview. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Text Diff
EnterLine-level difference between two texts (diff). 100% free, runs locally in your browser—nothing is uploaded to our servers.
Lorem Placeholder
EnterGenerate Latin placeholder paragraphs. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Image Tools
Format conversion, compress, resize, flip/rotate/filter, watermark, collage, EXIF, OCR, and more. 100% free, runs locally in your browser—nothing is uploaded to our servers.
HEIC to JPG
EnterConvert iPhone HEIC/HEIF photos to JPG in batch; multi-file ZIP download. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Image Format Convert
EnterConvert between PNG/JPEG/WebP, supports GIF first frame and SVG rasterization. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Image Compress
EnterBatch compress to WebP/JPG/PNG with max dimension and quality controls. 100% free, runs locally in your browser—nothing is uploaded to our servers.
PNG Compress
EnterBatch compress PNG with smart quantization or strict lossless mode. 100% free, runs locally in your browser—nothing is uploaded to our servers.
JPG Compress
EnterBatch compress to JPG with adjustable quality. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Image Resize
EnterBatch resize to uniform dimensions with contain/cover modes. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Image Crop
EnterSelect area or input pixel coordinates, export as PNG/JPG/WebP. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Image Proportional Scale
EnterScale proportionally by longest edge or fixed width/height, no distortion. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Image Watermark (Text)
EnterAdjustable position, opacity, and font size; batch export as ZIP. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Video Tools
Convert, trim, compress, GIF export, and audio extraction—processed locally with ffmpeg.wasm in your browser. 100% free, nothing uploaded.
Video Format Converter
EnterConvert between MP4, WebM, MKV, GIF, M4A, WAV, and more—locally via ffmpeg.wasm. 100% free, nothing uploaded.
Video to MP4
EnterConvert common videos to MP4 for playback and sharing—local ffmpeg.wasm. 100% free.
MOV to MP4
EnterConvert iPhone / Mac MOV files to MP4. 100% free, runs in your browser.
MKV to MP4
EnterConvert MKV to MP4 for wider player support. 100% free.
WebM to MP4
EnterConvert WebM downloads to MP4. 100% free.
AVI to MP4
EnterConvert legacy AVI to MP4. 100% free.
Video to WebM
EnterExport WebM for web embedding. 100% free.
Video to MKV
EnterExport MKV container format. 100% free.
Video Trimmer
EnterCut a clip by start/end time; stream copy or re-encode. 100% free, browser-local processing.
Encoding & Crypto
Base32/58/64, URL, Hex, escape, hash, HMAC, AES, RSA-OAEP, XOR, Vigenère, CRC32, QR code encode/decode, and more. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Base64
EnterEncode and decode text or files. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Base32
EnterRFC 4648 text encode/decode (commonly used for OTP/key display). 100% free, runs locally in your browser—nothing is uploaded to our servers.
URL Encode / Decode
EnterCommon encode/decode scenarios. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Hex (Hexadecimal)
EnterConvert between UTF-8 bytes and hexadecimal. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Escape & Entities
EnterHTML entities and JSON string escaping. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Hash Digest
EnterMD5, SHA-256, and other checksums and digests. 100% free, runs locally in your browser—nothing is uploaded to our servers.
HMAC
EnterHMAC-SHA1/256/384/512 in hexadecimal. 100% free, runs locally in your browser—nothing is uploaded to our servers.
AES-256-GCM
EnterPassphrase + PBKDF2 key derivation, local encrypt/decrypt. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Random Password / Token
EnterConfigurable length and charset, crypto-secure random. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Utilities
Timestamp, various IDs, unit conversion, ASCII, financial & phone validation, encoding tables, barcode, and other misc tools. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Timestamp Converter
EnterConvert between seconds, milliseconds, and date. 100% free, runs locally in your browser—nothing is uploaded to our servers.
UUID Generator
EnterBatch generate UUID v4 (crypto.randomUUID). 100% free, runs locally in your browser—nothing is uploaded to our servers.
ULID
EnterTime-sortable unique ID, batch generate. 100% free, runs locally in your browser—nothing is uploaded to our servers.
NanoID
EnterShort random string with customizable alphabet. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Unit Converter
Enterpx/rem and byte KiB/MB conversions. 100% free, runs locally in your browser—nothing is uploaded to our servers.
ASCII Table
EnterCharacter reference for codes 0–127. 100% free, runs locally in your browser—nothing is uploaded to our servers.
IBAN Validate
EnterMod 97 check digit validation. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Luhn
EnterBank card number mod-10 validation. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Phone Number
EnterParse and format to E.164 (libphonenumber-js). 100% free, runs locally in your browser—nothing is uploaded to our servers.
Web & SEO
Share card preview, robots/sitemap, CSP, Permissions-Policy, .env, security headers; plus URL/MIME, HTML/SVG/Markdown, UA, color, and accessibility tools. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Open Graph Preview
EnterFill in meta info and preview share card style (local simulation). 100% free, runs locally in your browser—nothing is uploaded to our servers.
robots.txt Generator
EnterCheck common rules and generate robots.txt text. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Sitemap Generator
EnterGenerate sitemap.xml fragment from URL list. 100% free, runs locally in your browser—nothing is uploaded to our servers.
CSP Builder
EnterToggle Content Security Policy directives and export header value. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Permissions-Policy
EnterFeature policy header builder with explanations. 100% free, runs locally in your browser—nothing is uploaded to our servers.
.env Parser
EnterPaste env file and view as table (one-click value masking). 100% free, runs locally in your browser—nothing is uploaded to our servers.
Security Headers Cheat Sheet
EnterCommon HTTP security header descriptions and one-click copy examples. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Whois Lookup
EnterQuery domain Whois information via RDAP protocol.
SafeLink Decoder
EnterExtract the real destination URL from SafeLink / redirect wrappers.
Documents & Productivity
CSV & Markdown tables, full-width/half-width, RMB uppercase, calendar & vCard, email headers, and more. 100% free, runs locally in your browser—nothing is uploaded to our servers.
CSV ↔ Markdown Table
EnterConvert between CSV and Markdown pipe table. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Full-Width / Half-Width
EnterConvert alphanumeric and common punctuation between full and half width. 100% free, runs locally in your browser—nothing is uploaded to our servers.
RMB Uppercase
EnterConvert amount to Chinese uppercase (yuan, jiao, fen). 100% free, runs locally in your browser—nothing is uploaded to our servers.
iCalendar Preview
EnterPaste .ics and list event summaries. 100% free, runs locally in your browser—nothing is uploaded to our servers.
vCard Parser
EnterDecode electronic business card fields into a table. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Email Header Parser
EnterUnfold folded lines and display key-value pairs. 100% free, runs locally in your browser—nothing is uploaded to our servers.
ID Card Validator
EnterValidate Chinese ID card number and extract info. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Chinese Traditional Colors
EnterTraditional color names with hex values, click to copy. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Relationship Calculator
EnterCalculate family relationship titles from relationship chain. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Development & APIs
GraphQL, OpenAPI, Properties, XML, SemVer, Mermaid, EditorConfig; plus JWT, config & JSON toolchain, SQL, networking & certificates, compression, and base conversion. 100% free, runs locally in your browser—nothing is uploaded to our servers.
GraphQL Formatter
EnterFormat query/mutation (graphql). 100% free, runs locally in your browser—nothing is uploaded to our servers.
OpenAPI Viewer
EnterTree-view browse and search Swagger JSON. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Properties ↔ JSON
EnterConvert between Java .properties and JSON. 100% free, runs locally in your browser—nothing is uploaded to our servers.
.editorconfig
EnterGenerate EditorConfig from tech stack presets. 100% free, runs locally in your browser—nothing is uploaded to our servers.
XML Formatter
EnterGeneral XML validation and indentation. 100% free, runs locally in your browser—nothing is uploaded to our servers.
SemVer Compare
EnterVersion validity, ordering, and diff (semver). 100% free, runs locally in your browser—nothing is uploaded to our servers.
Mermaid Preview
EnterRender flowchart/sequence diagram source (mermaid). 100% free, runs locally in your browser—nothing is uploaded to our servers.
Nginx Formatter
EnterFormat/beautify Nginx config files. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Docker Run → Compose
EnterConvert docker run command to docker-compose.yml. 100% free, runs locally in your browser—nothing is uploaded to our servers.
Tool and technology topics
Focused paths through Toolsku's most useful task-based tools and validated technical content.
PDF tools and workflows
Convert, compress, merge, split, extract, and organize PDFs with practical browser tools and task guides.
Image conversion and compression
Compress, resize, crop, OCR, and convert JPG, PNG, WebP, HEIC, and other image formats.
Text processing tools
Count, compare, search, replace, normalize, and transform text for writing and development tasks.
JSON and structured data
Format, validate, query, compare, and convert JSON, YAML, TOML, XML, CSV, and typed models.
Encoding, hashing, and QR
Encode and decode Base64, URLs, Unicode, hashes, QR codes, and common developer data formats.
AI agents in production
Practical comparisons and architecture guidance for agent frameworks, workflows, memory, evaluation, and safety.
AI and web protocols
Understand MCP, A2A, HTTP, transport, and the protocol choices behind interoperable agent systems.
Browser AI and WebAssembly
Run and optimize AI workloads in the browser with WebLLM, Transformers.js, WebGPU, and WebAssembly.