Cached rates and estimate fees
Save up to 12 pairs, inspect inverse published reference rates, and model a percentage deduction. This is not a live money-transfer fee estimate.
OPERAVA · How our tools workUtilities user guide.
Utilities user guide.
Clear by design.
Understand each tool's functions, limits, sources, cached data and privacy choices.
Documented · updated 20 October 2026
Free OPERAVA Utilities: User Guide
These online utilities are provided as-is for convenience, education and general workplace use. They are not financial, legal, political, health, engineering, tax or other professional advice. Files and data should always be verified before decisions, publication or distribution.
Online Currency Conversion
Open Currency Converter. Enter an amount, select source and target currencies, and press Refresh published rates. Results use the most recent reference dataset returned by ExchangeRate-API's public endpoint, not live interbank bids, bank quotes or guaranteed settlement rates. The provider's update time and any cached-data status are shown beneath the result.
The browser may save data for an individual source currency for six hours in local storage. A previously saved rate may also appear if the provider cannot be reached, with an explicit stale warning. Estimated spread and fixed fee inputs are illustrative, not an actual provider tariff. Compare actual bank or card prices and fees before any transaction.
Online PDF Viewer & Word DOCX to PDF
Open PDF & Word Converter. PDF viewing uses your browser's built-in PDF reader. Text-to-PDF uses the system print dialog. The Word tool accepts modern .docx documents up to 15 MB; choose a file, inspect the preview, set paper size and select Download PDF or the print fallback.
Word input is converted to semantic HTML using Mammoth and then rendered to a PDF using html2pdf.js. Fixed-version JavaScript libraries are loaded from cdnjs when requested. Your document contents are read in your browser and not intentionally transmitted to OPERAVA or the CDNs by this tool. However, loading external scripts contacts the external CDN, and trust in that provider is required. The files are not guaranteed to render pixel-perfectly: complex typography, pages, annotations, tracked changes, macros, charts, footnotes and accessibility metadata can change or be unsupported. Never treat generated PDFs as signed originals. Legacy .doc is unsupported.
Online Calendar & Notes
Open Calendar. Notes are saved in browser local storage (if allowed). Use export for one date or export all notes into an ICS calendar file. Clearing browser data, using private mode, or changing devices may permanently erase local notes. Back up important events. This is not a synchronized or cloud-backed calendar.
Online Scientific Calculator
Open Scientific Calculator. Enter expressions using numbers, parentheses, the operator buttons and functions such as sin, cos, sqrt or log. Select degrees or radians. Results use browser floating-point calculations and may contain rounding errors. The parser does not evaluate arbitrary JavaScript, and expression history is ephemeral.
Online HTML Viewer & Editor
Open HTML Editor. Import or type HTML (up to 2 MB for uploads), choose optional auto-preview and save an HTML file. The preview uses a sandboxed frame and blocks network requests, external resources and forms. Downloaded HTML will not necessarily be subject to the same sandbox policy; only open or distribute code you trust.
News, Politics & Research References
Open References. This is a nonpartisan, searchable directory of third-party official and independent sources. The listed sites are operated by their respective publishers, which may change content or terms without notice. Links are not an endorsement. Always verify dates, original documents, jurisdiction, opposing perspectives and updates directly with the source.
Caching & data policy
Public HTML pages may be cached briefly by browsers and Cloudflare for performance. Versioned page code can be refreshed by reloading. Exchange-rate snapshots are cached in your own browser for six hours with a visible source timestamp; external CDN scripts may be cached independently by your browser/CDN. Your calendar notes are browser-local, not synced. Word, PDF and HTML files selected through file inputs are processed in your browser; the tools do not include file upload endpoints. Some external resources (such as fonts, conversion-library scripts and exchange-rate providers) require network requests and operate under their own policies.
Privacy, accessibility and support
Tools are provided without an account, warranty or availability guarantee. For sensitive documents, consider an offline professional document application if third-party browser scripts are not acceptable. Keyboard controls, visible focus states, readable contrasts and responsive layouts are included; browser capabilities and extensions may affect behavior. For privacy matters, refer to OPERAVA Privacy Policy. For site assistance, use Contact OPERAVA.
Important disclaimer
OPERAVA provides these browser-based tools on an as-is, as-available basis. They do not establish a professional-client relationship, guarantee results, or replace verified records. Refer to applicable laws, professional standards and original providers for decisions with legal, financial, safety or other significant consequences.
New utility controls and limitations
All seven utilities include optional task-specific controls. Currency favorites and calendar backups are stored or created on your device; calculator memory is tab-only. PDF viewing still depends on the browser, and Word-to-PDF output must be reviewed for pagination and formatting.
Backup and restore
Search private notes; download and import JSON backups. Imports merge entries and replace notes with the same dates.
Temporary memory
Use M+, M−, MR and MC, or clear this tab’s recent calculation list.
File controls
Download the original selected PDF, preview text before printing, and set paper size, orientation and margins when downloading DOCX conversions. Browser print options are separate.
Find and replace
Track lines and bytes, search source, replace a selected match and wrap text in semantic bold tags.
Reading list
Save a browser-local list of public source URLs, filter saved sources and export the URLs as JSON. Bookmarking does not verify source accuracy.
Security and privacy: Browser storage is not appropriate for highly sensitive notes on shared devices. Document conversion depends on third-party JavaScript libraries loaded over HTTPS and may not reproduce exact Word layouts. Reference links remain third-party content. Verify consequential results independently.