Free Online Tools | Studio Tools

Handbook 7

Long-form guides that walk you through real decisions and show you which free tool helps at each step.

Finance Building an emergency fund and reserves: the complete guide September 20, 2026 · 15 min Energy Is solar worth it in 2026? PV systems, payback, balcony solar September 16, 2026 · 20 min Web & Tech Data formats: the essential file types, conversion and file sizes explained September 12, 2026 · 17 min

Playbooks & Workflows 19

All workflows

Guided workflows that chain several tools into one complete result. Not single tools, but full step-by-step journeys.

Workflow Security Setup Check a password, harden it and make it memorable. One connected workflow. 3 Steps 3 Tools Workflow Publish Content & SEO Optimize your text, check word count and create clean URL slugs. 4 Steps 4 Tools Workflow Complete Solar Check Yield, feed-in, funding and profitability in one guided pass. 4 Steps 4 Tools Workflow Image Workflow Filter, scale, convert and compress an image in one flow. 4 Steps 4 Tools Workflow From Salary to Pension From net salary through the statutory pension to the retirement gap. 3 Steps 3 Tools Workflow Home Purchase & Financing Side costs, financing and loan for buying property. 3 Steps 3 Tools

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Workflow Dev Launch Checklist Minify your code and run a launch audit. 4 Steps 4 Tools Workflow Freelancer: Quote to Invoice Hourly rate, e-invoice, SEPA QR, late interest and retention. 5 Steps 5 Tools Workflow Health & Weight BMI and calorie needs in one guided flow. 2 Steps 2 Tools Workflow Design & Brand Kit Color, contrast, gradient and favicon for your brand. 4 Steps 4 Tools Workflow Check an Incoming Invoice Verify the IBAN, recalculate VAT, pay via GiroCode and know retention duties. 4 Steps 4 Tools Workflow API & Auth Debugging Decode tokens, check timestamps and inspect payloads. 5 Steps 5 Tools Workflow Website Performance Optimize images and minify CSS, JS and HTML. 8 Steps 8 Tools Workflow Share a Screenshot Safely Remove personal data from screenshots before sharing. 4 Steps 4 Tools Workflow Clean Up a Data List Convert exports, remove duplicates, sort and verify. 5 Steps 5 Tools Workflow Event Kit WiFi QR, agenda QR, countdown and certificates for your event. 4 Steps 4 Tools Workflow Employed vs. Self-employed Compare net salary, hourly rate and pension gap. 3 Steps 3 Tools Workflow My First Own Flat Moving into your first flat, step by step: costs, furniture, insurance, handover. 9 Steps 9 Tools Workflow Prepare a Presentation Create a timeline, estimate speaking time, rehearse, build a handout. 4 Steps 4 Tools

Collection 89

Open Collection

Many small single-purpose tools, each with its own page and URL. Encoding, text, math, randomness and more, grouped in one place.

Security & Privacy 15

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Password Generator Generate secure, customizable passwords to your specifications for length, character types, and exclusion rules, suited to any account that needs protection. passwordsecurityrandom Password Checker Test your password security with a heuristic check analyzing length and patterns, so you can quickly spot potential weak points. GDPR-compliant. password strengthcheck password securitysecure password WiFi QR Generator Create a QR code with your WiFi credentials so guests can connect to your network instantly, without typing the login details. GDPR-compliant. wifi qr codewifi qr generatorshare wifi password

Text & Writing 13

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Word Counter Count words, characters, sentences, and paragraphs in your text and estimate the reading time, useful for blog posts, research papers, and long documents. word countcharacter counttext analysis Case Converter Convert text in real time between UPPER, lower, Title, and Sentence case, practical for formatting in texts, code, or headings. GDPR-compliant. case converteruppercaselowercase Lorem Ipsum Generator Generate filler text in the Lorem Ipsum style for layouts, designs, and print, with selectable amount and paragraph structure. GDPR-compliant. lorem ipsumplaceholder textdummy text generator

Images & Media 34

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QR Code Generator Generate QR codes from text, URLs, or any data without signing up, right in your browser, for content you want to share and open instantly. qr codecreate qr codeqr generator Image Compressor Compress images with adjustable quality, target size, and resolution without leaving the page, your images stay completely local on your device. compress imageresize jpegoptimize png Image Converter Convert images between PNG, JPEG, WebP, and more, fully client-side in your browser, without your images ever leaving your device. convert imagepng to jpegwebp converter

Numbers & Math 11

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BMI Calculator Calculate your Body Mass Index (BMI) and see which weight category you fall into, a useful orientation for health and well-being. GDPR-compliant. bmi calculatorbody mass indexweight Percentage Calculator Calculate percentages, proportions, and changes in three calculation modes, for commission calculations, discounts, or percentage shifts. GDPR-compliant. percentage calculatorpercent calculationpercentage change Calculator Free online calculator with standard and scientific modes, no signup required, for quick calculations of all kinds and sizes. GDPR-compliant. calculatoronline calculatorscientific calculator

Web & Development 32

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JSON Formatter Format, minify, and validate JSON data with syntax highlighting, keeping raw data readable or ready for efficient transfer. GDPR-compliant. json formatterformat jsonminify json Base64 Encoder / Decoder Encode text or decode Base64 data, for instance in email attachments and data URLs, whenever binary data must be transmitted as text. GDPR-compliant. base64encodedecode Hash Generator Generate cryptographic hashes with MD5, SHA-1, SHA-256, and SHA-512 from your text to verify data integrity or represent passwords securely. GDPR-compliant. hash generatormd5sha-256

Time & Date 7

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Date & Age Calculator Calculate days between dates, add or subtract days, and get the calendar week and day of the week, helpful for scheduling and date planning. GDPR-compliant. date calculatordays between datesage calculator Time Zone Converter Convert times between time zones, with date, time, and offset included, and organize your appointments across time boundaries. GDPR-compliant. time zone convertertimezone calculatorconvert time zone Countdown Timer Count down live to a target time with a large display, entirely in your web browser without any registration or setup. Runs in your browser, GDPR-compliant. countdown timercountdown onlinetime until date

Lifestyle 35

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Sticky Notes Create colorful sticky notes in your browser, position them by drag-and-drop, and export your notes as JSON for further processing. sticky notesonline notesbrowser notes Kanban Board Use a free Kanban board in your browser with drag and drop, persistence, and JSON export to organize your tasks clearly. kanban boardtask managementto do board Tip Calculator Calculate the tip and total amount, split between multiple people for a fair division, so everyone pays their share at a group meal. GDPR-compliant. tip calculatorcalculate tipsplit the tip

Business & Admin 23

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VAT Calculator Convert between net and gross with German VAT at the rates of 19 % and 7 %, ideal for accurate pricing in everyday commerce. GDPR-compliant. vat calculatorsales tax calculatornet gross calculator IBAN Validator Check IBANs with MOD-97 right in your browser, your input stays local, and instantly spot errors in your account data without delay. iban validatorvalidate ibaniban check SEPA QR Generator (GiroCode) Generate a SEPA-EPC QR code (GiroCode) from IBAN, name and amount, fully local and processed directly in your browser. sepa qrgirocodeepc qr code

Energy & Environment 8

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Solar Yield Calculator NEW Estimate the annual solar yield of your PV system based on region, orientation and roof tilt angle, entirely in your browser. solar yield calculatorphotovoltaic calculatorpv output estimate Solar Payback & ROI Calculator NEW Find out when your PV system pays off, with break-even time and expected return on investment, entirely local and private. Runs in your browser, GDPR-compliant. solar payback calculatorpv roi calculatorsolar break even germany Balcony Solar (Plug-in PV) Calculator NEW Work out whether your balcony solar system pays off, with calculated savings and required payback period, all local. Runs in your browser, GDPR-compliant. balcony solar calculatorplug in pv germanymini solar payback