Free, private tools that run in your browser
Convert and compress images, edit and sign PDFs, generate invoices, run financial calculators and more — all 100% in your browser. Your files and data never leave your device. No uploads, no sign-up, no watermark.
- 🔒 100% private — no uploads
- 🆓 Free, no watermark
- 📱 Works on any device
- ⚡ Works offline once loaded
How it works
Unlike most online tools, LocalTools never sends your files to a server — everything happens right here in the browser tab.
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Pick a tool
Choose from the image, PDF, document and calculator tools below. No account, no install, nothing to download.
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It runs on your device
The tool loads into your browser and does all the work locally — on your own computer or phone. Most keep working even offline once the page has loaded.
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Nothing is uploaded
Your files and the numbers you type never leave your device — there is no server to send them to. Completely free, with no watermark.
Learn the details
Short, practical explainers on file formats, compression, privacy, finance and the real problems these tools solve.
- How extra payments actually save money on mortgages and loans
Why the first years are almost all interest, how every extra dollar compounds the savings, and exactly what the amortization schedule is showing you. Numbers you can use with any calculator.
Read guide → - Digital signatures on PDFs: visible stamps vs real cryptographic signatures
What “Sign PDF” actually does, the difference between a picture of a signature and a cryptographic signature, why self-signed certs look untrusted, and what survives when you email the file.
Read guide → - How image compression actually works — and when it hurts quality
JPEG DCT blocks, PNG filters, WebP and AVIF, lossy vs lossless, generational loss, and exactly what the quality slider is trading. Practical rules for photos, screenshots, logos and print.
Read guide → - Inside a PDF: why files get huge and what compression actually changes
PDF objects, streams, xref tables, image vs text bloat, incremental saves, and the real difference between “compress images” and “restructure the whole document”. What you can safely shrink and what you cannot.
Read guide → - Professional invoices: what actually gets paid (and common mistakes)
Layout, required details, tax/VAT handling, payment terms, and the small things that make the difference between “I’ll get to it” and “paid today”. All in the browser, no account needed.
Read guide → - Compound interest, explained with real numbers
Why starting ten years earlier beats contributing twice as much, what monthly compounding actually does, and how to sanity-check any projection — including ours.
Read guide → - JPG, PNG or WebP? How to pick an image format
A practical decision guide to the three formats you actually meet: what each one is good at, where each one fails, and the conversions that make sense (and the ones that don’t).
Read guide → - Why PDFs get huge — and how to actually shrink them
A 40 MB PDF is almost never 40 MB of text. Where the size really comes from, which compression tricks work, and what you give up with each one.
Read guide → - Static vs dynamic QR codes — what “free” QR generators don’t tell you
Why QR codes from free generator sites stop working, how scan tracking works, and when a plain static code is simply better. Plus how error correction keeps damaged codes scannable.
Read guide → - Scanning documents with your phone: from photos to a clean PDF
You don’t need a scanner — you need decent light, a steady phone and the right way to turn the photos into a small, ordered, shareable PDF. Here’s the whole workflow.
Read guide → - Your photos know where you live: EXIF data, explained
Every phone photo carries hidden metadata — GPS coordinates, device details, timestamps. What’s actually in there, when it matters, and how to remove it before sharing.
Read guide → - How to send photos that are “too big” — without wrecking them
Email bounced your attachment, a form rejected your upload? Here’s why photos are so large, what actually makes them smaller, and how to shrink them without visible quality loss.
Read guide → - What is a HEIC file? The iPhone photo format, explained
Why your iPhone photos won’t open on Windows, what HEIC actually is, whether you should switch your camera to JPEG, and the fastest ways to convert when something refuses the format.
Read guide →
All tools
Every LocalTools utility, grouped by what it does.
Images → PDF
Turn any mix of JPG, PNG, HEIC, WebP or scans into one orderly PDF. Reorder pages visually, apply per-image compression and quality settings, and hit email or upload limits without ever sending your photos to a server. The result is a single, self-contained document that opens everywhere.
- Image to PDF ConverterTurn one or many images into a single, neatly compressed PDF — without uploading anything.
- JPG to PDF ConverterConvert and merge JPG (JPEG) images into a single PDF in seconds.
- PNG to PDF ConverterConvert PNG images to PDF and merge them into one document.
- HEIC to PDF ConverteriPhones save photos as HEIC, which many tools can’t open.
- WebP to PDF ConverterConvert WebP images — including transparent ones — into a single PDF.
- Compress Images to PDFNeed a smaller PDF for email or upload limits? LocalTools gives you real control: set the quality, maximum resolution, output format and even a target size in megabytes — for all images at once or for each image individually — and watch the estimated size update before you download.
Convert images
Switch between formats with control over quality and size. HEIC from iPhones becomes universal JPG or lossless PNG; WebP shrinks for the web while PNG keeps sharp edges for screenshots and diagrams. All processing happens locally so originals never leave your device.
- HEIC to JPG ConverteriPhones save photos as HEIC, which many apps and websites can’t open.
- WebP to JPG ConverterSaved a .webp image from the web and need a normal JPG? Drop your WebP files here and get JPG images back instantly — converted locally in your browser, nothing uploaded.
- PNG to JPG ConverterTurn PNG images into smaller, universally-supported JPG files.
- JPG to PNG ConverterConvert JPG (JPEG) images into lossless PNG files — handy when you need a format that won’t recompress, or a base for editing.
- HEIC to PNG ConverterConvert iPhone HEIC/HEIF photos into lossless PNG images — useful when you need PNG specifically, or a high-fidelity base for editing.
Compress images
Shrink photos and graphics for email, web or storage while choosing exactly how much quality to trade. Control global or per-image quality, cap the long edge, and see a live size estimate before you commit. Works on batches and keeps your originals private.
- Compress JPGMake your JPG images smaller for email, web uploads or storage — with real control over quality, resolution and even a target file size.
- Compress PNGShrink large PNG files — screenshots, logos and graphics — with control over resolution and format.
- Compress ImagesReduce the file size of any image — JPG, PNG, WebP, HEIC and more — with real control over quality, resolution, format and a target size in megabytes.
Remove metadata
Strip GPS location, camera model, timestamps, thumbnails and every other EXIF/IPTC tag from one photo or a whole folder. The pixels stay untouched; only the sidecar data is removed. Essential before sharing sensitive shots or posting publicly.
Watermark images
Add a text or logo watermark with full control over opacity, rotation, position, tiling and scale. Apply it to a single image or stamp an entire batch the same way. Runs entirely in the browser so your source artwork never touches a third-party service.
Favicon generator
Drop a logo or square image and get the complete modern favicon set: favicon.ico in multiple sizes, 16–512 px PNGs, Apple touch icon, and the exact HTML snippet to paste into your <head>. Everything is rendered at the right sizes locally.
Edit images
Crop, resize, rotate, adjust brightness/contrast, add text and shapes, apply filters, or remove backgrounds with an on-device AI model. The full editor and background removal run in your browser; export the result or feed it straight into the PDF or format tools.
Meme generator
Caption any of 400+ popular meme templates or your own photo with the classic Impact look. Drag captions, edit live, and export a clean full-resolution PNG with no watermark. Templates are self-hosted so the tool has no external dependencies at runtime.
Medical imaging
Free online NIfTI viewer for .nii / .nii.gz volumes, plus DICOM (.dcm) folders. Scroll axial/coronal/sagittal planes, window intensity, and switch to an interactive 3D volume render — WebGL only, no upload, no install, no patient data leaving your machine.
PDF pages
Merge, split, reorder, rotate or delete pages with a live thumbnail view. Compress image-heavy PDFs, add visible watermarks or page numbers, and apply cryptographic digital signatures — everything stays on your device even for confidential contracts and scans.
- Merge PDFCombine several PDFs into a single document.
- Compress PDFMake a PDF smaller without uploading it.
- Watermark PDFStamp a text watermark — DRAFT, CONFIDENTIAL, your name — across every page of a PDF.
- Add Page Numbers to PDFNumber the pages of a PDF in a few clicks.
- Split PDFPull specific pages out of a PDF into a new document.
- Organize PDF PagesRearrange a PDF exactly how you want it.
- Rotate PDFFix sideways or upside-down PDF pages and save the rotation into the file.
- Delete PDF PagesRemove unwanted pages from a PDF and download the rest.
- Sign PDFAdd your signature to a PDF without printing or signing up.
PDF → images & text
Export every page as crisp JPG or PNG at the resolution you choose, or pull the selectable text layer out as plain text. Useful for posting single pages, feeding into design tools, or making the content of a text PDF searchable and copyable without a desktop app.
eBook tools
Turn a text PDF into a reflowable EPUB or FB2 that adapts to any screen and font size on Kindle, Kobo, Apple Books and most e-readers. Scanned PDFs become fixed-layout EPUBs that preserve the original page images. All extraction and repackaging happens locally.
Generate invoices
Build professional invoices with line items, tax/VAT, logos and signatures using a block layout you edit directly on the page. Save reusable templates in the browser, calculate totals automatically, and export via print-to-PDF — your client data never leaves your computer.
Finance
Project mortgages with taxes, insurance and PMI plus full amortization schedules, run investment and FIRE calculators with compound growth and inflation adjustment, and model loan payoff or debt snowball strategies. Every number and chart is computed in your browser.
- Mortgage CalculatorEstimate your monthly mortgage payment — principal, interest, taxes, insurance and PMI — and see exactly how the loan is paid off over time.
- Investment CalculatorSee what your investments could become.
- FIRE CalculatorSee when you could reach financial independence.
- Loan CalculatorWork out the monthly payment on any fixed-rate loan.
- Debt Payoff CalculatorSee how long it takes to pay off a debt and what it costs.
Everyday calculators
Quick, focused tools for the calculations you do constantly: percentage of a number or change, BMI, tip splits and discount math. Live results, clean formulas, and no sign-up friction — open, compute, copy and close.
- Percentage CalculatorWork out percentages three ways: what is X% of a number, what percent one number is of another, and the percentage increase or decrease between two numbers.
- Percentage Increase CalculatorFind the percentage increase or decrease between two numbers.
- BMI CalculatorCalculate your Body Mass Index in metric (kg/cm) or imperial (lb/in) units.
- Tip CalculatorWork out the tip and split the bill in seconds.
- Discount CalculatorFind the sale price and your savings in a click.
Compare text
Diff any two versions of code, contracts, configs or prose side-by-side or unified. Word-level highlighting shows exactly what changed; ignore-whitespace and other options cut through formatting noise. The entire comparison is local and works offline.
Text & dev tools
One workbench for the daily text chores: live word/character counts, case conversion including camel/snake, JSON format+validate+tree view, Base64/URL encode-decode, JWT inspection, CSV⇄JSON, SHA hashes, UUID/ULID generation, HTML entities, slugify, Unix timestamps and regex testing with capture groups.
- Word CounterCount the words, characters, sentences, paragraphs and reading time in your text instantly as you type or paste.
- Case ConverterChange the case of any text — UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case or kebab-case — with one click.
- JSON FormatterBeautify, minify, validate and explore JSON instantly.
- JSON ValidatorCheck whether your JSON is valid and pinpoint what’s wrong.
- Base64 EncodeEncode any text to Base64 instantly — fully Unicode-safe, so emoji and non-Latin characters round-trip correctly.
- Base64 DecodeDecode Base64 back to readable text instantly, with full Unicode support.
- URL Encode / DecodePercent-encode text for safe use in URLs and query strings, or decode an encoded string back to readable text.
- JWT DecoderPaste a JSON Web Token to instantly see its decoded header and payload, plus readable issued-at and expiry times.
- CSV to JSON ConverterPaste CSV and get a clean JSON array of objects, using the first row as the keys.
- JSON to CSV ConverterPaste a JSON array of objects and get CSV back, with a header row built from the object keys.
- Hash GeneratorGenerate the MD5, SHA-1, SHA-256 and SHA-512 hash of any text or file at once.
- Unix Timestamp ConverterConvert a Unix timestamp to a readable date — or a date to a timestamp — instantly, in seconds or milliseconds.
- UUID GeneratorGenerate UUIDs in bulk — classic random v4 or time-ordered v7 — with your browser’s cryptographic random generator.
- Lorem Ipsum GeneratorGenerate classic lorem ipsum placeholder text by paragraphs, sentences or words.
- Regex TesterWrite a regular expression and see it match your text live — highlighted inline, with every match, position and capture group listed.
- ULID GeneratorGenerate ULIDs in bulk — 128-bit IDs that sort by creation time thanks to a millisecond timestamp prefix, then 80 bits of secure randomness, in 26 URL-safe Crockford Base32 characters.
- HTML Entity Encoder / DecoderEscape text so it displays literally in HTML — turning <, >, &, " and ’ into entities — or decode entities back to characters.
- Slugify — Text to URL SlugTurn a title or heading into a clean, URL-friendly slug — lowercased, with accents stripped and every run of punctuation or spaces collapsed into a single separator.
Password & tokens
Generate cryptographically strong passwords and random tokens with adjustable length and character classes, plus static QR codes (PNG or SVG) that never expire or phone home. Everything is produced by your browser’s secure random source and never transmitted.
- Password GeneratorCreate strong, truly random passwords with the length and character sets you choose.
- QR Code GeneratorTurn any text, URL or note into a QR code.
- Wi-Fi QR Code GeneratorMake a QR code that connects phones to your Wi-Fi with a scan — no spelling out the password.
- Token GeneratorGenerate cryptographically secure random tokens for API keys, secrets and session ids.
Unit converter
Convert length, weight, temperature, speed, volume, area, data and fuel economy in either direction with exact factors and handy reference tables. Popular pairs have dedicated deep pages; the hub shows every common unit at once so you can hop between scales quickly.
- Unit ConverterA fast, private unit converter.
- Length ConverterA fast, private length converter.
- Weight ConverterA fast, private weight converter.
- Temperature ConverterA fast, private temperature converter.
- Area ConverterA fast, private area converter.
- Volume ConverterA fast, private volume converter.
- Speed ConverterA fast, private speed converter.
- Data Storage ConverterA fast, private data storage converter.
- Fuel Economy ConverterA fast, private fuel economy converter.
- Centimeters to Inches ConverterConvert centimeters to inches — and back — in an instant.
- Inches to Centimeters ConverterConvert inches to centimeters — and back — in an instant.
- Meters to Feet ConverterConvert meters to feet — and back — in an instant.
- Feet to Meters ConverterConvert feet to meters — and back — in an instant.
- Miles to Kilometers ConverterConvert miles to kilometers — and back — in an instant.
- Kilometers to Miles ConverterConvert kilometers to miles — and back — in an instant.
- Kilograms to Pounds ConverterConvert kilograms to pounds — and back — in an instant.
- Pounds to Kilograms ConverterConvert pounds to kilograms — and back — in an instant.
- Grams to Ounces ConverterConvert grams to ounces — and back — in an instant.
- Ounces to Grams ConverterConvert ounces to grams — and back — in an instant.
- Celsius to Fahrenheit ConverterConvert celsius to fahrenheit — and back — in an instant.
- Fahrenheit to Celsius ConverterConvert fahrenheit to celsius — and back — in an instant.
- Miles per Hour to Kilometers per Hour ConverterConvert miles per hour to kilometers per hour — and back — in an instant.
- Kilometers per Hour to Miles per Hour ConverterConvert kilometers per hour to miles per hour — and back — in an instant.
- Megabytes to Gigabytes ConverterConvert megabytes to gigabytes — and back — in an instant.
- Gigabytes to Megabytes ConverterConvert gigabytes to megabytes — and back — in an instant.
- Liters to Gallons ConverterConvert liters to gallons — and back — in an instant.
- Gallons to Liters ConverterConvert gallons to liters — and back — in an instant.
- MPG to L/100km ConverterConvert mpg to l/100km — and back — in an instant.
- L/100km to MPG ConverterConvert l/100km to mpg — and back — in an instant.
Number base converter
See binary, octal, decimal and hex (plus any base 2–36) update together as you type. BigInt-backed so 64-bit and larger values stay exact — perfect for masks, permissions, memory addresses and debugging without leaving the browser.
- Number Base ConverterConvert between binary, octal, decimal and hexadecimal — all at once.
- Hexadecimal to Decimal ConverterConvert hexadecimal to decimal in an instant.
- Decimal to Hexadecimal ConverterConvert decimal to hexadecimal in an instant.
- Binary to Decimal ConverterConvert binary to decimal in an instant.
- Decimal to Binary ConverterConvert decimal to binary in an instant.
- Hexadecimal to Binary ConverterConvert hexadecimal to binary in an instant.
- Binary to Hexadecimal ConverterConvert binary to hexadecimal in an instant.
Color converter
Translate between HEX, RGB, HSL and approximate CMYK with an instant live swatch. Useful for pulling a color out of a design, converting brand tokens for CSS or print, and sanity-checking that a vivid screen color will survive in CMYK gamut.
- Color ConverterConvert colors between HEX, RGB, HSL and CMYK — all at once, with a live preview swatch.
- HEX to RGB ConverterConvert HEX to RGB with a live preview.
- RGB to HEX ConverterConvert RGB to HEX with a live preview.
- HEX to HSL ConverterConvert HEX to HSL with a live preview.
- RGB to HSL ConverterConvert RGB to HSL with a live preview.
- HSL to RGB ConverterConvert HSL to RGB with a live preview.
Looking for something specific? Search all tools →