Updated: April 27, 2012

Are you looking for an overview of the best iPhone App for Spanish to English / English to Spanish Dictionary iPhone App Review?

Full disclosure: While I work for none of these companies, Ascendo sent us a free trial of their software for review. The comparisons below are obviously skewed by my experience. I also need better coverage of Collins and Ultralingua, so please, app developers, contact me if you would like to see your app reviewed here.

NOTE: Grading Scale: 0=unavailable, 1=good, 2=better, and 3=best.

Discussion and Review

After recently spending time comparing these software packages (sorry, I have not yet purchased Ultralingua and Collins to properly compare them), I prefer the free Wordreference app and, for the excellent offline and navigation features, Ascendo over my previous recommendation of Oxford Spanish English Dictionary.

No matter which app you purchase, the most important criterion is the database--that is, whose dictionary source is "under the hood." After all, most app creators have arrangements with the finite number of high quality Spanish-English (paper) dictionaries on the market. Arguably though, Encyclopedia Britannica has lost to the crowd-sourced competition (Wikipedia), so you should unquestionably learn from that lesson too and install Wordreference, which contains an unparalleled breadth of dictionary translations.

The advantage of the printed dictionaries, now transferred digitally, is the vetted, sometimes peer-reviewed, nature of their content. The heavyweights in that arena are Collins and Oxford. Both are authorities in the English language and both contain extensive, high-quality articles. Depending on your source (excellent article here: http://www.learn-spanish-resources.co.uk/blog/spanish-dictionary/spanish...), the breadth of the Collins database is unrivaled, whereas Oxford's is considered "authoritative." Neither are free, though Oxford's is cheaper ($24.99 vs. $29.99 USA). Both are excellent. Honorable mention goes to Ultralingua.

WordReference:
• Advantages:
• Free!
• Unbeaten breadth of topics
• Disadvantages:
• Not available offline
• Required internet connection slows lookup

Ascendo Spanish / English Dictionary :
• Advantages:
• 665,746 entries and 263,000 translations
• like Ultralingua, typing your word simultaneously searches Spanish and English
• Disadvantages:
• Not free like WordReference

UltraLingua is another option:
• Advantages:
• 75,000 entries and 290,000 translations
• an auto-complete feature, which Ultra advertises as "search-as-you-go," which allows you to partially spell the word, then select from a list of results, saving you typing
• Disadvantages:
• Appears to be an abridged version of Collins. Why not spend $5 more for the unabridged version?
• Wikipedia offers a good analysis of UltraLingua in general though is not specific to Spanish (http://en.wikipedia.org/wiki/Ultralingua). Wikipedia cites a study in Texas which faults the software for inconsistency and relative lack of regional dialects

The Oxford Spanish English Dictionary (OSD)
• Advantages:
• 75,000 entries and 290,000 translations
• fast auto-complete feature
• many articles (entries) are very high quality, especially popular ones like querer and ser. Oxford's content is outstanding here.
• Disadvantages:
• compared to Collins, certain words are missing, albeit unusual words

The Collins Spanish English Dictionary - Complete and Unabridged
• Advantages:
• It claims to contain 315,000 words and references
• Search feature allows phrase-level searching, not simply word-level searching
• It seems to actually contain more words than the Oxford Spanish Dictionary (OSD). For example, empicotar,empedernir (yes, these are unusual words, but OSD doesn't have them)
• Disadvantages:
• It's pricetag of $29.99 (USA 5-10-2011) makes it a more expensive option than most (e.g. $24.99 for OSD)