About rtbcrid.com
rtbcrid.com is a small, hand-built collection of free in-browser tools for developers and ad-tech engineers. Nothing is uploaded, nothing is stored, and nothing requires a signup. Open a tool, paste your data, get your result, close the tab.
What this site is
rtbcrid.com hosts a growing set of single-purpose web tools. Each one solves a small, sharply defined problem that comes up regularly in ad-tech and general web development: rendering an OpenRTB creative payload, beautifying or validating JSON, escaping strings for SQL or HTML, decoding URL-encoded values, diffing two blobs of text, converting JSON to CSV, transforming lists with a prefix or suffix. The list grows whenever a daily-driver task turns out to need yet another quick utility.
The whole site is static. Each tool is, in most cases, a single self-contained HTML file with the JavaScript inlined. There is no build step on your side, no NPM install, no Docker container, no account. The tool loads, runs in your browser, and that is the end of the interaction.
Why it exists
There is a peculiar gap in the market for tools at this level. The two ends are well served: commercial SaaS suites bundle hundreds of utilities behind a subscription and a signup flow, and open-source libraries on GitHub let you do anything if you are willing to clone a repo, install dependencies, and read documentation. What is missing is the middle: a clean, ad-free, no-friction web page for the small task you have right now.
The free tool sites that already exist are often heavy: dozens of trackers, modal popups asking for newsletter signups, mid-content ad blocks that wrap around the input panel. They work, but they are unpleasant. The premise of rtbcrid.com is that a tool page can be light, readable on a phone, free, and still pay its hosting bill. The display ads that exist sit in dedicated slots outside the tool area, and the tool itself stays clean.
What makes it different
A few principles that show up in every page on the site:
- Purely client-side. Every transformation, parser, renderer or formatter runs inside your browser. The HTML file is the application; once loaded, it does not call out to a backend.
- Nothing uploaded. Your data — the JSON you paste, the URLs you decode, the creative payload you render — does not leave your machine. There is no server-side processing of user content. There is no server-side storage of user content.
- Minimal analytics. Standard page-view analytics so I know which tools to invest more time in. No event-level tracking of what you type into the input boxes. No third-party fingerprinting scripts.
- No signup. No login, no email gate, no "free trial". The tools are free in both senses: free to use and free of friction.
- No ads inside the tools. Banner placements live in clearly demarcated zones at the edges of the page. The input and output panels are clean.
Who is behind it
rtbcrid.com is built and maintained by a single ad-tech engineer. I have spent most of the last decade working on programmatic advertising systems — bidders, SSP integrations, VAST renderers, fraud detection, header bidding wrappers — and along the way I built a personal collection of small browser utilities to handle the tasks that show up daily: rendering a creative to verify a payload, decoding a tracking URL, beautifying a packed JSON blob from a partner's log.
At a certain point the collection was big enough and stable enough that publishing it as a public site cost almost nothing. The result is rtbcrid.com. There is no team, no investor, no roadmap committee — just one developer maintaining the tools they want to keep using themselves.
Technical principles
The site is built around a few opinionated rules:
- Privacy first. If a feature can be implemented client-side, it must be. The only data leaving your browser is the standard set of headers your browser sends and basic page-view analytics. Tools never POST your content anywhere.
- Browser-native. No heavy frameworks. The tools rely on the built-in capabilities of modern browsers:
JSON.parse,URLSearchParams,fetch, the Streams API, the Clipboard API. Where a niche library is needed (a CSV parser, a diff algorithm, a JSON5 parser) it is loaded as a single minified file, not as a 200-package dependency graph. - No framework bloat. No React, no Vue, no build pipeline. Just HTML, CSS and modern JavaScript. This keeps load times in the tens of milliseconds, even on a phone.
- Single-HTML-file approach. Each tool ships as a self-contained page. You could save it to disk and run it offline. That portability is deliberate: when you need a tool you trust, you should be able to keep it.
- Semantic HTML. Headings are headings, lists are lists, forms are forms. Screen readers and "reader mode" both work without special handling.
About the name
The two halves of the name are core ad-tech terms. RTB stands for Real-Time Bidding — the auction-based mechanism that decides which ad shows in a given impression, usually within 100 milliseconds. CRID stands for Creative ID — the identifier that an ad system uses to refer to a specific creative asset (image, video, HTML5 unit) inside a bid request or response. Together they capture the corner of the industry the site grew out of: programmatic advertising, where milliseconds and IDs are everything.
The name also doubles as a sanity test. If "RTB" and "CRID" mean anything to you, the tools here are likely to feel familiar. If they do not, the more general developer tools — JSON beautifier, URL decoder, escape/unescape, diff — are the natural entry points.
What is coming next
The roadmap is long but unsorted. Tools planned for the next few months include a CSV-to-JSON reverse converter, a base64 encoder/decoder with smart detection, a regex tester scoped specifically to common ad-tech URL patterns, and a VAST tag inspector. A long-form blog is also being filled in gradually, covering topics like how OpenRTB actually works, the mechanics of header bidding, common pitfalls in impression tracking, and the differences between the various creative formats. You can browse the existing posts on the blog.
Suggest a feature or report a bug
Email is the only contact channel. There is no Twitter account, no LinkedIn profile attached to the site, no Discord server. If you have an idea for a tool, a bug to report, or a question, write to ipaladin1993@gmail.com. I read every email, and most useful suggestions end up in the queue.
Particularly welcome: edge cases the existing tools mishandle, with a minimal reproduction (the exact input you pasted, the browser you used, what you expected and what happened). That kind of report is gold.
How the site is monetised
Honest disclosure, because a free site with no signup raises the obvious question. The site runs display advertising in clearly marked banner slots, with a header-bidding wrapper feeding multiple SSPs and Google AdSense as a fallback. Those ads sit in fixed positions outside the tool itself; they never wrap, interrupt, or interact with the input or output panels. No data you paste into a tool is ever fed into an ad system or any third party.
That is the entire revenue model. There is no premium tier, no paid plan, no enterprise edition. If the ads bother you, an ad blocker will not break any tool — every feature works with ads disabled, because none of the tooling depends on ad scripts.