As mentioned before, Twitter has some limits, such as you can post no more than 140 characters, only see a total of 800 tweets on the home page, follow no more than 1000 users per day, and so on.
Besides, you can only search those tweets (Twitter messages）posted in about 7 days, the older ones won’t be searchable, though they are still on the Twitter site.
If you want to search your own old tweets, you can back up them in advance, and then search the backup files. But another easy way is to search them with the following top 10 websites, no matter what you are going to search:
The Topsy website will allow you to search old tweet back to one or two years.
With advanced search, you can search tweets posted in a particular time, with or without any keywords, within a site or domain, and so on.
For the results, you can filter them by posted time (such as past hour, past day, past 5 days, etc. ), you can search tweets with links, photos or the experts who mention your search terms, and you can view the photos in full size on the Topsy site directly for photo search.
The ReSearch.ly website allows you to search the tweets with a keyword from a place and / or a community.
You can filter the results by male or female, positive or negative, and Top RT, you can search the tweets back to a particular day, and you can also track the keywords, mentioned times, positive / negative ratio, and popularity of the search term with analytic charts.
Without registration, you can search only for 10 times, and after signing up for a free account, you will have 7 days trial, which you can expand up to 90 days by posting your search results on Twitter.
3. Tweet Scan
Tweet Scan can search tweets back to a few months.
You can search tweets with any keywords from a particular username, reply to the tweets via the site, or search the identi.ca website besides Twitter.
But Tweet Scan is not stable, since some terms are not searchable, for example, you can search “nuts” directly, but not “freenuts”, unless you click the “To search further back” link.
Google Realtime search is a database of Twitter messages now, you can change the timeline, read the three top updates, or view the full conversation of a reply tweet.
But there will be some tweets missed, since Google hasn’t and won’t indexed all the messages from Twitter.
Besides Realtime, you can also use the Google web search to find old tweets, just by entering the following characters after your search term:
Then you can also choose the time range on the left sidebar to filter the results.
Yahoo also offers real-time results from Twitter.
On the left sidebar of any search result page, there is a Twitter icon, clicking on which, you will have the results from Twitter only.
Or you can search old tweets directly by adding the following characters after your keywords:
The search engine Bing also index and offer tweets.
With advanced search, you can add the domain “Twitter.com” to search, then you will get the results from Twitter only, and you can also filter the tweets by countries or languages.
Or you can search tweets directly by adding the following characters after your keywords:
Among Google, Yahoo and Bing, Google is the best search engines for you to search old tweets, since it offers more results, and you can filter the results by time.
The Searchtastic website lets you search old tweets from months ago, up to 30 pages, less than 3000 messages.
You can search all the tweets from a user or his / her following, all the tweets about a keyword, or all the tweets with a keyword from a user, you can expand shortened URLs, you can view the popular hashtag and search the related tweets.
For the results, you can export them to excel for backup, click any word and add it to the search, or remove the search terms by clicking the related words under the search box.
The BackTweets website only allows you to search tweets with links.
For free account, you don’t need to register, and you can search Tweets with links back to about 2 weeks. You can search more after upgrade. And you can also add a bookmarklet to your Bookmarks Toolbar.
9. Snap Bird
With Snap Bird, you can search old tweets back to about 10 days.
Sign in with your Twitter account, then you can search any keyword within your friends’ tweets, your direct messages, or any user’s favorites.
By the way, you need to enter a Twitter username as well as the keyword to complete the search.
Since many people has synced their tweets to FriendFeed, you can search it and find some old tweets.
You can use advanced search to specify the search terms, though you can’t filter the results by Twitter. You don’t need to register to search, but you can save, comment, like or share the results after login.
Among the above 10 websites, only Topsy, Google, Yahoo, Bing and FriendFeed support Chinese search, and Topsy is the most powerful I think, since it offers the most results.