ctftime.org

CTFtime does not publish a public formula for its team ratings, so the exact math is not something you can reproduce from the site alone. What the site does show is the outcome: a yearly, ordered rating table where each team gets a numeric score, and that score is used to rank teams against each other. If you want to know where a team stands, the rating page is the authoritative view; if you want to know precisely how a score was derived, CTFtime does not expose that.

What the rating page actually shows

The Team rating section lists one table per year, with columns for place, team, country, and rating. For example, the 2026 table begins:

Earlier years follow the same structure with different leaders — r3kapig tops 2025 at 1589.023, kalmarunionen tops 2024 at 1721.038, and so on back through the archive. The country column exists in the layout but is empty in the data shown here, so you should not assume a team's country is always populated.

Two things are worth noticing in that table. First, ratings are not on a fixed 0–1000 scale: values range from roughly 600 into the 1700s across years, so a rating only means something relative to other teams in the same year. Second, the top rating in a year is not stable — 1721.038 in 2024 versus 1231.551 in 2026 — which tells you the scale shifts year to year rather than being an absolute skill measure.

How the rating is used

The rating drives the ordering of the table, so its main function is comparison: it lets you see which teams performed best in a given year and how far apart they are. Because each year has its own table, the intended comparison is within a year, not across years. A team ranked 1st in 2026 and a team ranked 1st in 2024 both hold the top place, but their rating numbers are not directly comparable.

The rating also sits alongside the rest of CTFtime's team features — team pages, member lists, and the ability to create a team — so it functions as the public scoreboard for a team's competitive record.

What determines a team's rating

CTFtime's own pages do not state the inputs to the calculation. Based on how CTF rating systems generally work, a team's score would reflect which events it played and how it placed, with stronger fields and harder events carrying more weight — but that is a general expectation, not something CTFtime documents on the pages available here. Treat any specific claim about event difficulty weighting or opponent strength as unverified unless you find it stated on the site.

Practical takeaways

• To check a team's standing, use the Team rating page and select the year — the table is the source of truth.
• Compare ratings only within the same year's table.
• Do not read the raw number as an absolute skill level; it is a relative ranking value that resets in scale each year.
• If you need the exact methodology, CTFtime does not publish it in the material available, so plan around the published rankings rather than trying to recompute them.

CTFtime.org is a community-run hub for Capture The Flag (CTF) competitions. It aggregates upcoming, running, and past CTF events, tracks team ratings, and collects writeups. If you want to find a CTF to play, check how a team ranks, or read solutions after an event, this is the site to use. It is not an event organizer itself; it indexes and links to competitions run by others.

What you can find on CTFtime.org

The site is organized around a few core areas:

• Upcoming events — CTFs that have not started yet, so you can plan participation.
• Now running — events currently in progress.
• Past events — an archive of finished competitions.
• Tasks — challenge listings tied to events.
• Writeups — community-submitted solutions and explanations, including a "New writeups" feed.
• Calendar — a date-based view of the CTF schedule.
• Teams — team profiles, member lists, and the ability to create a new team.
• Rating — historical team rankings by year.
• Compare — a tool to compare teams.
• FAQ and Contact us — support and general information.
• For organizers — a section aimed at people running CTFs.

Team rating explained

The rating section shows yearly leaderboards. Each entry includes a place, team name, country, and a numeric rating. For example, in the 2026 table the top three are TeamH4C (1231.551), H-T8 (1054.843), and W4llz (990.256). Earlier years show different leaders, such as kalmarunionen (1721.038) in 2024 and Dragon Sector (1092.135) in 2019.

Ratings are year-scoped, so a team's position reflects its performance within that year rather than a single all-time score. Use the year selector to view a specific season.

Who it is for

• Players looking for events to join and teams to follow.
• Teams wanting to track their standing and compare against others.
• Learners reading writeups to understand how challenges were solved.
• Organizers listing competitions and reaching participants.

How to use it

1. Browse Upcoming events to find a CTF that fits your schedule.
2. Check the Rating page for a given year to see where teams stand.
3. After an event, read Writeups to study approaches you missed.
4. Use Teams to create a team or view members.
5. Use Compare when you want to weigh two teams side by side.

The site's value is in aggregation: it saves you from hunting across many separate event pages and gives a consistent view of schedules, results, and solutions in one place.

Open ctftime.org and use the Upcoming events section on the homepage to see what's next, or go to the Calendar page for a month-by-month view. Both are free to browse without signing in. The site lists events by start time, and each event links to a detail page with the format, organizers, and registration info. If you want to filter by date range or look further ahead, the Archive and Past events sections cover what has already run.

Where the event listings live

CTFtime's navigation (visible in the site header) includes these relevant entries:

• Upcoming – events that haven't started yet
• Now running – events currently in progress
• Past events – completed events
• Calendar – a date-based view of the schedule
• Archive – historical event data

The homepage surfaces Upcoming events, Now running, Past events, and New writeups as separate blocks, so you can scan the near-term schedule at a glance without navigating away.

Step-by-step: finding an event

1. Go to the homepage. The Upcoming events block lists the next competitions in chronological order.
2. Scan the list for a date that works for you. Each entry shows the event name and its scheduled time.
3. Click the event name to open its detail page. This is where you find the format (Jeopardy, Attack-Defense, etc.), the organizers, and any links to the event's own site or registration.
4. Check "Now running" if you want to see what's live right now — useful if you're looking to spectate or join a CTF that has already started.
5. Use the Calendar when you want to plan further out. It lays events across a monthly grid so you can spot clusters or gaps.
6. Browse Past events or the Archive to see how a recurring event was run previously, which helps you judge whether it's worth entering next time.

What each event page tells you

Once you open an event, the detail page typically covers:

The weight field matters if you care about ratings: CTFtime's team rating is calculated from event results, and each event carries a weight that affects how much a placement moves your rating. Higher-weight events (often larger, more established CTFs) have more impact.

Practical tips

• Time zones: CTFtime displays times in UTC by default. Convert to your local time before committing — a 48-hour event starting Friday 00:00 UTC may begin at an awkward hour where you are.
• Team vs. solo: Most listed events are team competitions. If you don't have a team, the Teams section lets you browse existing teams, and there's a Create new team option.
• Registration is separate: CTFtime lists the event, but signing up usually happens on the organizer's own site. Follow the event's links to register.
• Writeups as a preview: The New writeups block on the homepage shows recent solutions. Reading writeups from a past edition of an event is a good way to gauge difficulty before you enter.

Common snags

• An event shows in "Upcoming" but has no registration link yet. Organizers sometimes publish the CTFtime entry before opening sign-ups. Check back closer to the date.
• You can't find a specific event. Try the Archive or search by year — older or smaller events may not appear on the homepage.
• Times look off. Confirm you're reading UTC, not your local zone. The calendar view can make date boundaries clearer.

Browsing events, the calendar, and past archives requires no account. Signing in is only needed for actions tied to a team profile, such as rating participation or managing team membership.

CTFtime lets you create a new team from the "Create new team" link in its main navigation, and it lets you browse existing teams through the Teams and Rating sections. To join an existing team, you generally need to contact that team directly — CTFtime itself does not appear to offer a public "apply to join" button. You'll need an account (there's a "Sign in" link) before you can create a team or be listed as a member.

Creating a new team

1. Sign in to CTFtime. The site shows a "Sign in" entry in its navigation, so an account is the starting point.
2. Go to the "Create new team" link, which appears alongside "Teams" and "Rating" in the top navigation.
3. Fill in the team details and submit. The exact form fields aren't shown in the available page evidence, so treat the on-page form as the source of truth.
4. Once the team exists, you can add members. CTFtime lists a "Get team members" link, which is how a team's roster is retrieved or managed.

Expected result: your team gets its own page, and it can appear in team listings and, once it competes in rated events, in the rating tables.

What a team page shows

Based on the site's structure, a team is associated with:

• Members — via the "Get team members" function.
• Rating — teams appear in the yearly "Team rating" tables with a place, team name, country, and a numeric rating (for example, the 2026 table lists TeamH4C at 1231.551 and H-T8 at 1054.843).
• Participation history — events a team has played feed into the Past events and rating data.

Joining an existing team

CTFtime's navigation does not show a join-request feature. The practical path is:

1. Find the team you want. Use the Teams section or the Rating tables (filterable by year, e.g. 2026 back to 2011) to identify active teams. Ratings give you a rough sense of how competitive a team is — the top of the 2026 table sits around 1231, while 2025's leader (r3kapig) is at 1589.023.
2. Contact the team outside CTFtime. Teams typically coordinate through their own channels (Discord, IRC, social media, or a website). CTFtime doesn't publish a standard application flow, so the team decides how it recruits.
3. Get added as a member. Once accepted, the team adds you to its roster, which is what "Get team members" reflects.

If you want to compete immediately without recruiting, creating your own team is the lower-friction option — you can start solo or with a few people and grow later.

Choosing between creating and joining

Common sticking points

• No visible join button. Don't expect to request membership on CTFtime itself; reach out to the team directly.
• Ratings are yearly and event-driven. A team only builds rating by playing rated CTFs, so a brand-new team won't appear in the tables until it competes.
• Account required. Creating a team and being listed as a member both sit behind the "Sign in" step.

For organizers, CTFtime also provides a "For organizers" section, which is separate from team management and relevant if you're running an event rather than joining one.

CTF writeups on CTFtime are public, post-event solution notes written by players or teams, and they are most useful when you treat them as worked examples rather than answer keys. CTFtime aggregates them in a "New writeups" feed and links them to past events, so you can find how a specific challenge was solved, what tools were used, and where the solver got stuck. They help you learn fastest if you attempt the challenge first, then compare your approach with the writeup.

What a CTF writeup actually contains

A typical writeup walks through one challenge from start to finish:

• The problem statement — category (web, pwn, crypto, reversing, forensics, misc), points, and any provided files or URLs.
• Reconnaissance — how the solver inspected the target, e.g. reading source, running file/strings, or checking HTTP responses.
• The key insight — the vulnerability, weakness, or trick that unlocks the challenge.
• The exploit or solution — commands, scripts, or payloads, often with the reasoning behind each step.
• The flag — sometimes included, sometimes redacted.

Because they are written after the event, writeups usually reflect the solver's cleaned-up reasoning, not their real-time confusion. That makes them readable but also means you should not expect every dead end to be documented.

Where writeups live on CTFtime

CTFtime surfaces writeups in a few connected places:

The site's own description lists "CTF writeups" alongside teams, ratings, and the archive, so writeups are a first-class part of the platform rather than an afterthought.

How to use writeups to actually learn

Reading a writeup passively teaches you very little. A better loop:

1. Pick a past event from the archive and choose a challenge in a category you want to improve.
2. Attempt it yourself first — even 20–30 minutes of genuine effort makes the writeup far more instructive.
3. Read the writeup only after you're stuck or done, and compare: did you miss a tool, a class of bug, or a piece of domain knowledge?
4. Reproduce the solution on your own machine instead of just reading it.
5. Note the reusable pattern — e.g. "JWT alg:none bypass," "format string leak to bypass ASLR" — not just the flag.

For example, if you are learning web exploitation, search past events for a web challenge, try it locally, then read two or three writeups for the same challenge. Different solvers often take different routes, and seeing the alternatives is where the real learning happens.

Common pitfalls

• Spoilers before effort. Reading the writeup first removes the productive struggle that builds skill.
• Copy-paste without understanding. A working exploit you don't understand won't transfer to the next challenge.
• Assuming one writeup is complete. Some omit setup, dependencies, or failed attempts; cross-check with another if something doesn't run.
• Outdated tooling. Older writeups may use tools or versions that have changed, so adapt rather than copy verbatim.

Who benefits most

Writeups are valuable if you are:

• New to CTFs and want to see how challenges are structured and solved.
• Preparing for a specific category and want a bank of worked examples.
• Stuck on a live or past challenge and need a nudge past a single blocker.

They are less useful if you only want final flags, or if you read them without attempting the challenge. Used as a study companion after real effort, CTFtime's writeup feed and event archive are one of the most practical free resources for building CTF skills.