Creating a Web Link to the Entrez Databases

Created: October 16, 2006

Updated: April 25, 2008

Creating a Web Link to the Entrez Databases

This user guide provides instructions on creating a Web link or bookmark to PubMed and the other Entrez databases.

Users intending to send frequent queries or retrieve large numbers of records from Entrez should use the Entrez Programming Utilities (E-Utilities). Users must comply with the User Requirements to prevent overloading NCBI systems.


NLM currently leases PubMed journal citations, at no charge.

Retrieve PubMed Citations

Base URL:

To retrieve results in HTML or text format use PubMed Unique Identifiers (PMID).

  • Retrieval parameters:


Retrieve by PMID in AbstractPlus:,18276893

Retrieve by PMID in MEDLINE text format:,18276893?report=medline&format=texttop link

Search PubMed


PubMed antioxidant chocolate citations

  • activating Limits (PubMed Help):
    • cmd_current=Limits
    • pmfilter_filter name = filter value
  • turning off Limits
    • pubmedfilters


PubMed hay fever citations published in 2006, display the first 50:[pdat]&dispmax=50

PubMed citations on AZT limited to the AIDS subset:

To turn off PubMed Limits and search for hay fever displayed in the Citation format:

PubMed citations for the Text Word p21 and MeSH term Humans in the LinkOut display format:[tw]+AND+humans[mh]&report=externallinktop link

PubMed Feature Pages

Other Entrez Databases

  • retrieve records in HTML or Text format using unique identifiers
  • search with terms
  • link to related records or neighbors

Base URL:

To retrieve results in HTML or text format use unique identifiers (primary IDs). Use Search to retrieve by accession numbers.


Gene Full Report for GeneIDs 40048 & 847,847&dopt=full_report


Protein sequence records in text format for GIs 9367031, 729567, 586553 link


Use search to create a web link for terms with or without Boolean operators. “Escape” spaces by converting them to plus signs (+), e.g., Biochem Soc Trans should be Biochem+Soc+Trans.

You may also use Details to generate a search URL.

Base URL:

Protein records for AAC72193[accn] in the GenPept display:[accn]&doptcmdl=GenPept

Nucleotide records for COMT sequences in the Brief display:

OMIM records for the FBN1 gene in the Detailed display:[gene]&doptcmdl=detailedtop link


Display the related records (neighbors) or Entrez links for records using the unique identifiers (primary IDs), you may not use accession numbers.

Base URL:


Related Article citations for PubMed PMID 10495220:

Nucleotide links from PubMed PMID 10492167:

PubMed links from Nucleotide GI 47717105: link


A string with no internal spaces that identifies the resource that is using Entrez links. This argument is used to help NCBI provide better service to third parties generating Entrez queries from programs. As with any query system, it is sometimes possible to ask the same question different ways, with different effects on performance. NCBI requests that developers sending batch requests include a constant 'tool' argument for all requests using the utilities.

Example:tool=resourcetop link

Email Address

If you choose to provide an email address we will use it to contact you if there are problems with your queries or if we are changing software interfaces that might specifically affect your requests. If you choose not to include an email address you can sign up for utilities-announce to receive general announcements.

Example: name@institution.orgtop link

Display Formats

Display Formats for Sample Entrez Databases

Note: Scripts/programs that import XML should use E-Utilities.

Database  Display Format
PubMed DocSum, Brief, Abstract, AbstractPlus, Citation, MEDLINE, XML, ASN1, ExternalLink
Nucleotide DocSum, Brief, GenBank, ASN1, FASTA, ExternalLink, XML, Graph, fasta_xml, gbc_xml
OMIM Detailed, Synopsis, Variants, ASN1, XML, ExternalLink 
Gene DocSum, Full_Report, ASN1, XML, Gene_Table, ExternalLink
Protein DocSum, Brief, GenPept, ASN1, FASTA, ExternalLink, XML, graph, fasta_xml, gpc_xml
Genome DocSum, Brief, ASN1, ExternalLink, XML, Protein Table, cDNA FASTA, Protein FASTA, Structural RNA Table, Contig Table
Structure DocSum, Brief
PopSet DocSum, Brief, ASN1, ExternalLink
Taxonomy DocSum, Brief, TxUidList, TxInfo, TxTree, ExternalLink, XML

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