One Hub for Every File Tool. 100% Private & Free.
Compress, convert, merge, and edit your PDFs and images directly inside your browser. No accounts, no subscriptions, and zero files ever leave your device.
Merge PDF
Combine multiple PDF files into a single unified document in seconds.
Intelligent PDF Stream & Target Optimizer
Adaptive multi-pass binary convergence engine that compresses embedded scans, raw RGB bitmaps, and bloated metadata to hit exact target limits (<100KB, <200KB, <2MB) with zero blurry text artifacts.
Split PDF
Extract individual pages or page ranges into separate PDF documents.
Images to PDF
Convert multiple JPG, PNG, or WebP images into a clean single PDF.
Rotate PDF
Permanently rotate upside-down or sideways PDF pages by 90°, 180°, or 270°.
Perceptual Image Target Optimizer
Smart edge-preserving image compressor that hits exact KB/MB target limits while keeping diagrams, typography, and screenshots razor-sharp.
Image Format Converter
Convert between JPG, PNG, WebP, and SVG formats in milliseconds.
Resize Image Dimensions
Change pixel dimensions (width/height) with aspect ratio lock.
QR Code Generator
Create custom high-resolution QR codes for websites, WiFi, and contacts.
File Hash & Checksum
Calculate SHA-256, SHA-1, and MD5 checksums to verify file integrity.
Deep In-Archive ZIP Compressor & Container Optimizer
Unpacks nested Word documents, PDFs, and high-res images in browser memory, runs deep stream compression, and repacks with DEFLATE Level 9 to hit your target size.
Smart DOCX Deep-Compressor (OLE & PDF Stream Optimizer)
Industry-first in-memory OLE compound scanner that compresses embedded PDFs, screenshots, and graphics down to exact target limits (<2MB, <500KB) while preserving 100% typography, layout, and visual crispness.
Word & Character Counter
Live character, word, sentence, and reading-time analyzer.
Text Case Converter
Convert text to UPPERCASE, lowercase, Title Case, camelCase, and slug.
Base64 Encoder / Decoder
Encode text or files into Base64 format or decode Base64 back to plain text.
JSON Formatter & Validator
Beautify, validate, and minify JSON data with instant syntax error detection.
Markdown to HTML Converter
Live Markdown editor and instant HTML converter with real-time preview and export.
Text Diff Checker
Compare two texts or code snippets side-by-side to highlight additions and deletions.
Add Watermark to PDF
Stamp custom text watermarks across all PDF pages with customized opacity and angle.
Add Page Numbers to PDF
Insert clean page numbers into your PDF with custom position and numbering format.
Remove Duplicate Lines & Sort
Clean lists by removing duplicate lines, trimming extra whitespace, and sorting alphabetically.
Lorem Ipsum Dummy Text Generator
Generate placeholder filler text by paragraphs, sentences, or words with optional HTML formatting.
URL Encoder & Decoder
Encode or decode strings to safe percent-encoded URI format with real-time bidirectional conversion.
Strong Password Generator
Generate cryptographically secure passwords with custom lengths, symbols, and live strength meter.
SVG to PNG Converter
Convert vector SVG graphics into high-resolution PNG images with transparent backgrounds and custom scaling (1x to 8x).
WCAG Color Contrast Checker
Check foreground and background color contrast ratios for WCAG 2.1 AA and AAA accessibility compliance.
PX to REM & CSS Unit Converter
Convert between Pixels (px), REM, EM, Percent (%), and Viewport units (vw, vh) with customizable base font size.
Why Hearthhammer Is Different
Traditional online converters upload your personal documents and images to their cloud servers. We built Hearthhammer with modern browser WebAssembly so your files never leave your device.
Guaranteed 100% Privacy
Bank statements, identity proofs, and private photographs are processed strictly in local RAM memory. No risk of data breaches.
Zero Upload Wait Times
Skip sluggish upload bars. Since processing happens on your own CPU and graphics engine, transformations finish in milliseconds.
No Subscriptions or Watermarks
No "3 free tasks per day" paywalls. Enjoy unlimited file conversions supported cleanly by lightweight non-intrusive ads.
Frequently Asked Questions
Everything you need to know about our browser-powered file toolkit.
Are the tools really 100% free?
Yes! Every single tool is completely free with no hidden charges, premium tiers, or limits on how many files you can process.
How can you process files without uploading them?
Modern web browsers are capable of running powerful WebAssembly and native JavaScript libraries. We leverage your browser's local computing power to compress images, merge PDFs, and execute conversions without ever transmitting your data.
Will my downloaded files have any watermark?
Never. All converted and compressed files are 100% clean, original, and free of any watermarks or branding.
What devices and browsers are supported?
Hearthhammer runs smoothly on Chrome, Safari, Firefox, Edge, and mobile browsers on iOS and Android devices without requiring any extension or app installation.