Creative Specifications

Please contact your Crimtan Client Services contact if any creative falls outside these minimum specifications or if it is not listed here.

Insertion orders and creative must be submitted at least four working days before campaign launch date. For more information contact us on 020 7821 6864 or email

All campaigns will be invoiced based on Crimtan server statistics.


Crimtan has been certified to meet the IAB Gold Standard which aims to raise standards in digital advertising and ensure a sustainable future for the industry. Crimtan was the first company to issue a Primary Agreement and Digital Trading Statement that provides agencies with complete transparency about how we protect advertisers’ brands online. We were first awarded a JICWEBS DTSG Seal (view certificate) in May 2014, renewed in May 2015, 2016, 2017 and 2018 – and added JICWEBS Ad Fraud Seal in 2018 (view certificate). These cross industry set of best practice standards aim to minimise the risk of display advertising placement on inappropriate content.


The Better Ads Standards & L.E.A.N

The Coalition for Better Ads was created by leading international trade associations and companies involved in online media to improve consumers’ experience with online advertising. The Better Ads Standards provide insight into consumers’ ad experiences and identify those more preferred by consumers.

The IAB’s L.E.A.N. Ads program sets out best practice principles that aim to minimise ad blocking by consumers due to a poor user experience online.

Crimtan supports the Better Ads Standards initiative and L.E.A.N and actively discourages advertisers from using desktop and mobile ad formats that fall beneath a threshold of consumer acceptability.

Display Advertising General Specifications

  • Unit Sizes


    120 x 600
    160 x 600
    300 x 250
    300 x 600
    468 x 60
    728 x 90
    970 x 250


    160 x 600 (expandable to 600×600)
    300 x 250 (expandable to 600×250)
    728 x 90 (expandable to 728×315)

  • File types

    Image: JPEG, PNG, GIF

    Flash: SWF (Flash versions 4-10)
    ! Due to major browser limitations in supporting Flash it is highly recommended that HTML5 or image creatives are supplied.

    HTML5: JavaScript, JPEG, PNG, and GIF

    HTML5 Video: suitable for cross-browser delivery – discuss with your campaign manager


    Ads must not exceed 50% of a user’s CPU.

    Creative coding must not use cross-domain scripting or set cookies in unapproved domains.

    All landing pages must be crawlable

    All creatives must:

    • Be free of applications including, but not limited to, ActiveX, viruses, exit pops, spyware, and malware.
    • When clicked, landing page should open in a new tab/window.
    • Creative must include a minimum 1px border of contrasting colour to the background colour of the creative.
  • Maximum file size

    Initial: 150K maximum

    Total load size*: 2.2 MB maximum

    *Total load size includes initial and subsequent/polite loads

    NB. Smaller file sizes can improve loading speeds and inventory reach.

  • Video and animation duration

    Maximum animation length: 30 seconds

    Maximum host-initiated play: 30 seconds

    Maximum 3 loops with overall maximum duration of 30 seconds

    Audio – User initiated

  • Maximum frame rates

    Video – 24fps

    GIF- 12fps

For HTML5 Creatives

  1. HTML5 creative files should be provided in a ZIP-archive format which contains all files in one folder. No subfolders are supported.
  2. ZIP archives should contain one HTML file called index.html. All other files, if any need to be within the same folder.
  3. Total files sizes after archiving should not exceed 150KB.
  4. Creative must include a minimum 1px border of contrasting colour to the background colour of the creative.
  5. All calls from HTML5 creative, including those within the index.html file need to be secure.

The requirements above are applicable to HTML5 creatives hosted on Crimtan’s side. HTML5 creatives hosted externally only need to be compliant with requirements outside this section.

Pre-roll Video Assets Best Practices

  • Video

    File format: .mov or .mp4

    Dimensions: 1280×720, 1920×1080, or 1440×1080

    Aspect ratio: 16:9 or 4:3

    Codec: H.264

    Frame Rate: 23.98 or 29.97

    Bitrate: At least 20 Mbps

    Length: 15 or 30 seconds

    File size: Up to 500MB (smaller the size the better)

    Black bars: No black bars

    Letterboxing: No letterboxing

  • Audio

    Codec: PCM (preferred) or AAC

    Bitrate: At least 192 Kbps

    Bit: 16 or 24 bit only

    Sample rate: 48 kHz

    Audio settings: Required

  • Optional Companion Creatives

    Companion banner size 20K.

    Companion can be an image or HTML5.

    Companion banner animation time should be 15 seconds.

    Companion banner 18-24 FPS.

    Include 300×250, 728×90, and 300×60 companion banner options.

Mobile Advertising General Specifications

  • IMG files (gif/jpg/png format) or HTML mobile creative must be provided – with impression and click trackers in addition to any other tag types. Third party tags are accepted, however they may result in limited reach.
  • Creative must be approved at least 48 hours prior to campaign launch.
  • Creative must include a minimum 1px border of contrasting colour to the background colour of the creative.
  • As a minimum a 320×50 / 300×50 format must be provided for any campaign targeting smartphones.
  • HTML 5 mobile creative: maximum size 150KB and 2.2MB polite load
  • Best Practice: For times when a user’s browser does not support creative functionality (e.g HTML5), please provide a standard image file.
  • Smartphone
    Dimensions Max file size
    300 x 50 25 KB
    banner (Wide)
    320 x 50 25 KB
  • Tablet
    Dimensions Max file size
    Leaderboard 728 x 90 50 KB
    MPU 300 x 250 50 KB
  • Feature phone
    Dimensions Max file size
    Small 120 x 20 3 KB
    Medium 168 x 28 4 KB
    Large 214 x 36 5 KB
  • Rich media
    320 x 480)
    Max file size
    300 x 50 50 KB
    banner (Wide)
    320 x 50 50 KB

Pre-roll Video Assets Best Practices

  • Tracking

    • If you are not using a major third party adserver, please provide instructions for third party click tracking.
  • Supported creative

    • HTML5, gif, jpg, png.
    • Due to incompatibility with mobile and tablet devices we do not accept Flash® tags.
  • Pixels

    • We are able to utilise existing Crimtan pixels.
    • If we are implementing Crimtan pixels please ensure they are implemented and firing at least 48 hours prior to campaign live date.
    • Pixel type, placement and quantity to be discussed prior to signing IO.
  • Rich Media

    • Crimtan works with most commercial rich media companies. All rich media applications, such as video or DHTML, should occur within the standard purchased pixel space. Expanding units must be user initiated.
  • Animation | Looping

    • Total animation time may not exceed 30 seconds and may not exceed 3 loops of animation within the 30 second limit.
    • Ads may not employ persistent rapid or “strobing” animation of any graphic, copy or background elements.
  • Audio

    • Audio default state is mute and activation must be user-initiated on click.
    • Audio shut-off functionality must be clearly visible to the user.
  • Ad expansion

    • Ad expansion must be user-initiated
    • Ad expansion or contraction functionality must be clearly visible to the user
    • The method of ad expansion and contraction must be the same (e.g. rollover or click)
    • Close on roll off or must have [x] or “close [x]” on upper right corner of ad
  • Video

    • Video time may not exceed 30 seconds unless it is streamed, in which case there are no time restrictions
    • Video can play on initial load or be user-initiated via rollover or click
    • Audio must be user-initiated by click
  • Distinctive content

    • Ads must not be designed to mimic news or editorial content
    • Ad content must be clearly distinguishable from normal web page content and have clearly defined borders

Advertising Policy

All advertisements are subject to approval by Crimtan. Crimtan reserves the right to refuse any ad submission which does not meet the requirements specified above, or is deemed otherwise inappropriate, distracting, or harmful to the online user experience. Please also see our Advertising Terms & Conditions.