What a Salesforce ID converter does
Every Salesforce record has an ID. The one you see in a browser address bar has 15 characters, and it is case sensitive: a capital letter and a lowercase letter mean different things. Reports, the API and most integrations use an 18-character ID instead, which adds three characters at the end so the ID is safe in tools that ignore case.
This Salesforce ID converter turns the short form into the long form. Paste one ID or a few thousand, one per line, and read the result in a table. IDs that are already 18 characters are checked, so a mistyped or lowercased ID is caught rather than passed along.
How the extra three characters are worked out
The rule is public. Cut the 15 characters into three groups of five. For each group, look at each character in turn and note whether it is a capital letter. That gives five yes or no answers, which are read as a five-bit number with the first character counting least. The number, from 0 to 31, picks one character from the string A to Z followed by 0 to 5.
The three characters you get, in order, are the suffix. Because the suffix depends only on which letters are capitals, two IDs that differ only in case get different suffixes. That is the whole point, and it is why Excel's VLOOKUP, which ignores case, can still match 18-character IDs safely.
Reading the table
Each line gets a status. Converted means a 15-character ID was lengthened. Valid means an 18-character ID has the right suffix. Wrong checksum means the last three characters do not fit the first fifteen, and the table shows what they should be. That usually means someone retyped the ID or a tool changed its case. Wrong length and bad characters point to a copy and paste problem, such as a stray space or a cut-off ID.
The object column reads the first three characters, called the key prefix. 001 is an Account, 003 a Contact, 00Q a Lead, 006 an Opportunity, 701 a Campaign, 005 a User and 500 a Case. Custom objects begin with a letter a, and their prefix is set by your own org, so the converter reports them as custom rather than guess a name.
Limits
The converter checks the form of an ID, not whether the record exists. It cannot tell you that a record was deleted or that you lack access to it. The prefix list covers the common standard objects and may not name every object in your org. An unfamiliar prefix is reported as unknown.
Frequently asked questions
How do I convert a 15-character Salesforce ID to 18 characters?
Paste it into the box above and the 18-character form appears in the table. In Salesforce itself, a formula field with CASESAFEID(Id) gives the same result for every record.
Why does Salesforce have both 15 and 18-character IDs?
The 15-character ID is case sensitive, which breaks in tools that ignore case, such as Excel lookups. The 18-character ID adds a three-character suffix that encodes which letters were capitals, so it stays unique even when case is lost.
Are the 15 and 18-character IDs the same record?
Yes. The first 15 characters of an 18-character ID are the 15-character ID. Salesforce accepts either form in most places, and the 18-character form is safer in spreadsheets and integrations.
What does the first part of a Salesforce ID mean?
The first three characters are the key prefix, and they identify the type of object. 001 is an Account, 003 is a Contact and 00Q is a Lead. Custom objects have prefixes that start with the letter a.
Are my IDs uploaded anywhere?
No. The conversion runs in your browser. The IDs you paste are never uploaded, stored or logged.