Security
X.509 Certificate Decoder
Review bounded X.509 fields and supplied chain links.
Local
Utiloom online tools
Work with PDFs, data, images, and public web evidence
Process files, validate data, inspect public web evidence, and export results with clear limits and processing disclosures.
Start with a reviewed workflow
Browse all toolsCategories
Find the right workspace
Developer
34Format and validate structured data, inspect APIs, generate implementation assets, and debug browser-facing formats.
Security
4Inspect public certificates and calculate modern unkeyed hashes locally without collecting secrets.
Text
5Join, count, compare, clean, and transform text for documents, data, and implementation workflows.
Image
17Resize, convert, compress, crop, watermark, inspect, and export visual assets locally.
SEO
22Inspect public web evidence, metadata, crawl controls, domain authentication, and search publishing readiness.
Date, Time & Planning
9Coordinate time zones, meetings, calendar events, schedules, date and time simulation for testing, and lightweight personal planning workflows.
Calculator
17Handle date, age, unit, body, and numeric calculations in a clean browser UI.
File
8Create and inspect ZIP archives, verify checksums, inspect file evidence, and compare folder manifests.
Convert PDF pages, extract text, add visible numbering, combine images, and organize documents locally.
What Utiloom is
Small, honest tools for work that does not deserve a new app
Utiloom is a library of browser-based utilities for developers, marketers, content teams, and anyone who regularly needs to convert, check, or clean up a file before moving on with their day. Most tasks here take under a minute: reformat a JSON payload, resize a folder of images, verify a download checksum, decode a certificate, or find a meeting time that works across three time zones. There is no account, no upload queue, and no trial period.
The catalog is intentionally curated rather than exhaustive. We have retired more tools than we currently publish, because a tool that produces a vague score or a guessed result is worse than no tool at all. What remains is a set of utilities we use ourselves, each with a working interface, stated limits, worked examples, and answers to the questions people actually ask about it.
How your data is handled
Local by default, and clear when it is not
Most tools on this site process your input entirely inside your browser using the Web APIs already available there: file readers, the Canvas element, Web Crypto, PDF.js, and similar libraries. Your file is never sent to our servers, and closing the tab discards it. That is why image, PDF, ZIP, hash, and formatting tools are safe to use with internal documents and unreleased assets.
A smaller group of tools has to make a network request to do its job: checking a public site's redirects, headers, or TLS certificate, or looking up the SPF and DKIM records of a domain you own. Those pages carry a visible “Network” label, state what is sent and to whom, and never ask for anything private. The Trust Center explains the three processing modes and what each one means for retention.
Start here
Tools people come back to
These are the pages with the most repeat use. Each one has a sample input you can load to see the output before pasting your own data.
Security
Hash Generator
Create modern text hashes locally.
Local
Date, Time & Planning
Calendar Event Generator
Create downloadable ICS calendar events.
Local
Developer
CSV Viewer & Cleaner
Profile, clean, and convert CSV data locally.
Local
File
File Checksum Verifier
Strictly calculate and verify SHA-256 file checksums.
Local
Image
Image Watermark Tool
Preview, apply, and verify batch watermarks.
Local
By category
What you can get done here
Developer Tools
The developer section is where most of the daily traffic goes. It covers the payloads and config files that pass through a normal workday: formatting and validating JSON, comparing two JSON documents, testing a regular expression against sample text, turning a cURL command into fetch or Python code, converting YAML to JSON, and tidying SQL, CSS, or HTML before a code review. Every formatter reports a parse error with a line and column instead of silently guessing.
Security Tools
Security tools stay deliberately small. You can decode an X.509 certificate to check its subject alternative names, issuer, and expiry, calculate SHA-256 and other unkeyed hashes for a file or text, and check the certificate chain a public hostname presents. We removed password and secret-based tools from the public catalog so that nothing on the site asks you to paste credentials.
Text Tools
Text tools handle the small editing chores that are awkward in a word processor: counting words and characters against a limit, comparing two drafts line by line, switching between title case, sentence case, and snake_case, scoring readability, and joining a list into a delimited string for a query or a tag field.
Image Tools
Image tools run entirely in the browser, which matters when the files are product photos, screenshots with customer data, or unreleased designs. Resize and convert a batch to WebP, crop to an exact aspect ratio, add a visible watermark, rasterize an SVG, generate favicons and app icons, or inspect and strip location metadata before an image is shared publicly.
SEO Tools
The SEO section focuses on things you can actually verify about a page: how a title and description will render in a search snippet, whether robots.txt blocks a URL, whether an XML sitemap is well formed, whether hreflang tags point at each other correctly, and what a technical audit of a public URL reveals about redirects, headers, and canonical tags. Structured data generators produce JSON-LD you can paste straight into a page.
Date, Time & Planning
Planning tools solve coordination problems across time zones and calendars. Find a meeting slot that works for people in three cities, convert a timestamp between zones, generate a calendar event file that opens in Google Calendar or Outlook, keep a world clock for a distributed team, or track job applications through interview stages without a spreadsheet.
Calculator Tools
Calculators show their working. Loan and mortgage schedules list every payment, the compound interest calculator separates contributions from growth, the business-days calculator respects the holidays you enter, and unit, percentage, BMI, and age calculators explain the formula they apply. Financial results are arithmetic illustrations, not advice, and each page says so.
File Tools
File tools cover the moments when you need to package, check, or understand files without installing anything. Build a ZIP archive from files or a folder, inspect an archive's entries before extracting them, verify downloads against a SHA256SUMS manifest, identify a file's real type from its bytes rather than its extension, or produce a folder tree for documentation.
PDF Tools
PDF tools use PDF.js and browser rendering to work on documents locally. Convert pages to PNG images, extract the text layer, run OCR on scanned pages, merge or reorder pages, add visible page numbers, or combine a set of images into a single PDF. Nothing is uploaded, which is usually the reason people look for these tools in the first place.
How the library is maintained
What a tool has to do to stay on the site
Every published page has to pass the same checks: the interface works with real input, the limits are stated on the page rather than discovered by trial and error, the guide describes what the tool actually does, and the examples produce the output shown. When a format or a platform changes, the page is updated or the tool is retired and its URL redirected to the closest replacement. We publish maintenance notes on the Updates page and describe our review process in the Editorial Policy.
If a tool gives you a wrong result, or you need one that is not here, the Contact page reaches the maintainer directly. Bug reports with the input that failed are the fastest way to get something fixed.